Colorado II – Colorado River Steamship

The Colorado II was a stern-wheel paddle steamer (sternwheeler) that operated on the Colorado River from 1862 until it was dismantled in 1882. It was the second vessel of that name and the fifth steamboat overall on the lower Colorado River. It played a key role in freight and passenger transport supporting military posts, mining, and settlement in the desert Southwest during the peak of river steamboating.

Colorado II in a tidal dry dock in the shipyard above Port Isabel, Sonora - MacMullen, Jerry, Paddle-Wheel Days in California, Stanford University Press, 1944
Colorado II in a tidal dry dock in the shipyard above Port Isabel, Sonora – MacMullen, Jerry, Paddle-Wheel Days in California, Stanford University Press, 1944

Background and Construction

Steamboat service on the Colorado River began in the early 1850s to supply Fort Yuma (near present-day Yuma, Arizona) and other points upriver, as overland transport across the desert was difficult and expensive. George A. Johnson & Company dominated the trade. The original Colorado (often called Colorado I), launched in late 1855, was a 120-foot sternwheeler that could carry about 60–70 tons on a shallow draft of under two feet. It used an 80-horsepower engine and was captained at times by Isaac Polhamus (later known as the “Dean of the Colorado River”).

By 1862 the original Colorado was worn out. Its hull was dismantled in April 1862 at Arizona City (Yuma). The engine and boiler were removed and reused. Shipbuilder John G. North (a well-known California steamboat builder) constructed a new, larger hull in San Francisco. The parts were shipped to the Colorado River and assembled/launched at Arizona City under the guns of Fort Yuma, due to fears of Confederate raiders during the Civil War. The new vessel—Colorado II—entered service around December 1862 (some sources note May or later in the year for full operations).

Specifications

  • Type: Stern-wheel paddle steamer (sternwheeler)
  • Tonnage: 179 tons
  • Length: 145 feet
  • Beam (width): 29 feet
  • Draft: Approximately 16 inches (very shallow, suited to the river’s sandbars and variable water levels)
  • Engine: 80 hp steam engine reused from Colorado I
  • Cargo capacity: Around 70 tons (some accounts note higher freight capacity in practice; one source cites capacity for 179 tons of freight, aligning with displacement)
  • Builder: John G. North (hull); machinery from the prior vessel
  • Owners: George A. Johnson & Company, later the Colorado Steam Navigation Company (C.S.N.Co., reorganized 1869)

These shallow-draft design features were essential for navigating the lower Colorado’s shifting channels, sandbars, and seasonal low water.

Role on the Colorado River

Colorado II operated primarily on the lower Colorado River, from the river mouth/delta area (near Port Isabel, Sonora, Mexico, on the Gulf of California) northward past Arizona City/Yuma, to landings serving mining districts, military posts (including Fort Mohave), and settlements in present-day Arizona, California, and Nevada. It carried freight (supplies, mining machinery, ore, wool, agricultural goods), passengers, and often towed barges to increase capacity.

It was part of Johnson’s fleet that held a near-monopoly after absorbing rivals in the 1860s. Key captains included Stephen Thorne. The vessel worked alongside others such as the Cocopah (I and later II), Mohave, Nina Tilden, and barges. Woodyards (often staffed by local Cocopah people) supplied fuel along the route. Trips supported the growth of mining (e.g., in areas like Eldorado Canyon) and military logistics. By the late 1860s–1870s the company (reorganized as C.S.N.Co.) ran multiple steamers and handled thousands of tons of freight and hundreds of passengers annually. Colorado II is documented in period photos, including at Fort Yuma landings and in a tidal dry dock at Port Isabel.

Competition from rival lines (e.g., in the mid-1860s) was short-lived. The arrival of the Southern Pacific Railroad at Yuma in 1877 (with a bridge soon after) sharply reduced the need for long-haul river transport, as rail took over east-west traffic. The steamboat company was sold to Southern Pacific interests. Remaining boats, including Colorado II, continued for a time on residual upper-river and local service.

Ultimate Fate

Colorado II remained in service until 1882, when it was dismantled (sources consistently list 1882; some note August). This was typical for aging Colorado River steamboats once machinery wore out or traffic declined—hulls were often broken up, and usable parts reused or the vessels beached. It outlasted several contemporaries (e.g., Cocopah II was dismantled around 1881). The broader steamboat era on the lower Colorado effectively ended with the construction of Laguna Dam (completed around 1909), which blocked navigation, though limited operations continued a few years longer with smaller vessels.

Colorado II exemplifies the practical, shallow-draft sternwheelers that opened the desert Southwest to reliable waterborne commerce for roughly three decades before railroads and dams rendered them obsolete. Primary details come from historical compilations of Colorado River steamboats, including Wikipedia summaries drawing on period accounts and works such as those referencing MacMullen’s Paddle-Wheel Days in California.

Mohave II – Colorado River Steamship

Mohave II (also referred to as Mohave) was a stern-wheel steamboat and the largest vessel ever to operate on the Colorado River. It was the first and only double-smokestack (twin-stack) steamboat on the river, giving it a distinctive silhouette that resembled the larger, more ornate Mississippi River packets in outward appearance, though its interior was utilitarian and geared toward practical freight and passenger work rather than luxury.

Mohave II at Yuma, Arizona, with Sunday school group embarked, 1876 - Unknown author - MacMullen, Jerry, Paddle-Wheel Days in California, Stanford University Press, 1944
Mohave II at Yuma, Arizona, with Sunday school group embarked, 1876 – Unknown author – MacMullen, Jerry, Paddle-Wheel Days in California, Stanford University Press, 1944

Physical Description and Design

Built by San Francisco shipbuilder Patrick Henry Tiernan (the same builder of the earlier Gila), the Mohave II was constructed in sections in San Francisco, disassembled, shipped to the Colorado River Delta, and reassembled at the shipyard in Port Isabel, Sonora, Mexico (at the mouth of the Colorado River). It was launched in May 1876.

Key specifications included:

  • Displacement/tonnage: 188 tons.
  • Length: 149.5 feet.
  • Beam (width): 31.5 feet.
  • Draft: Approximately 1 foot (12 inches) of water—shallower than the Gila by about half a foot—which allowed it to navigate farther into shallow sloughs, sandbars, and low-water conditions than most other boats on the river.
  • Hull depth: Roughly 3–3.1 feet.
  • Propulsion: Stern-wheel paddle design, optimized for the Colorado’s shallow, shifting, sandbar-filled waters and strong currents.
  • Distinctive features: Twin smokestacks (the only such configuration on the river), contributing to its “palatial” or “magnificent” advertising image for excursions.

Despite its imposing external look, it was primarily a working vessel designed to tow barges and carry substantial cargo while also accommodating passengers for both commercial and recreational trips. Its shallow draft made it especially versatile for the challenging lower Colorado River environment.

History of Usage

The Mohave II was built by the Colorado Steam Navigation Company (C.S.N.C., formerly George A. Johnson & Company) specifically to replace the worn-out Mohave I (a 1864 stern-wheeler that had been dismantled in 1875 at Port Isabel, with its machinery later reused elsewhere). It entered service in 1876 and operated for about a quarter-century until around 1900.

It served as a key freight, passenger, and towboat during the peak and gradual decline of Colorado River steamboating. Primary roles included:

  • Hauling ore, mining machinery, supplies, wool, and other goods to support mining booms (including later gold discoveries in areas like the Searchlight and Goldroad districts) and agricultural trade in the American Southwest.
  • Transporting troops, merchants, settlers, and tourists.
  • Towing barges (sometimes multiple) for heavier loads.
  • Supporting railroad construction, notably assisting with the wooden railroad bridge at Needles in the early 1880s by towing barges equipped with pile drivers.
  • Special excursion and pleasure trips, including Sunday school outings (famously photographed at Yuma in 1876), May Day and Fourth of July picnics, trips to islands or points of interest, and even longer voyages into the Gulf of California (one noted 10-day pleasure trip in 1895 under Captain Jack Mellon).

Notable captains and operators associated with it included Isaac Polhamus (and family members), Joseph H. Godfrey (nephew of Polhamus, who took it to its farthest recorded point), and John Alexander “Jack” Mellon. Under Godfrey in 1881, it reached Rioville (at the mouth of the Virgin River in Nevada), the practical highest point of steam navigation on the lower Colorado during high water—extending roughly 450–600 miles upstream depending on conditions and measurement from the mouth or Yuma.

The boat helped sustain the C.S.N.C.’s dominance on the river even as railroads began encroaching in the late 1870s–1880s (the company was eventually linked to or sold interests involving the Southern Pacific). Business fluctuated with mining activity; a late-1890s revival kept the Mohave II and Gila busy enough that a new barge (Enterprise) was needed. By the late 1890s, however, rail competition and aging vessels reduced operations. In early 1900, as the company shifted resources (reusing the Gila’s engine for the new Cochan to serve Searchlight mines), the Mohave II was stripped of its machinery, run into Jaeger’s Slough near Yuma, and left to decay (dismantled around January 1900). Broader Colorado River steamboating effectively ended with the completion of Laguna Dam (about 14 miles above Yuma) in 1909, which blocked upstream navigation.

Ports of Call and Routes

The Mohave II operated primarily on the lower Colorado River, with Yuma (Arizona Territory/Arizona; formerly Arizona City, near Fort Yuma) as the principal hub and supply center after the railroad reached it. Standard commercial runs covered roughly 450 miles or more upstream during suitable water levels, connecting the Gulf of California/delta region to upriver mining, military, and settlement points. Wood yards and landings along the route supplied fuel (often cut by local Cocopah and other Indigenous workers).

Key ports of call and landings associated with its service and the broader C.S.N.C. fleet (which it shared routes with) included, from downstream to upstream (approximate historical distances and activity periods where noted):

  • Delta/estuary area (Sonora and Baja California, Mexico): Port Isabel (shipyard and major anchorage/port until the late 1870s), Robinson’s Landing, Port Famine, Lerdo Landing, Gridiron, Ogden’s Landing, and others for cargo transfer from ocean vessels (to minimize Mexican customs issues) and wood.
  • Lower river near Yuma: Jaeger City/Colorado City area, Fort Yuma/Yuma (core hub for passengers, freight, military supply, and excursions).
  • Mid-river Arizona/California points: Castle Dome Landing, Picacho, Ehrenberg (important mining/freight transfer), La Paz area, Parker’s Landing/Camp Colorado, Liverpool Landing, and others serving ranches, mines, and ferries.
  • Upper mid-river: Needles (California; grew in importance with the railroad and bridge construction in the 1880s, where Mohave II assisted), Fort Mohave (Arizona Territory; major military post and regular stop), Hardyville (Arizona Territory; practical head of navigation at low water, near present-day Bullhead City area; key ferry and freight point), El Dorado Canyon (Nevada; silver mining support), and Mohave City.
  • Farthest reaches (high water): Rioville (Nevada, mouth of the Virgin River; reached in 1881), with occasional service toward Callville or related Mormon supply points earlier in the steamboat era.

Routes typically ran between the Gulf/delta or Yuma and Hardyville/Fort Mohave as the practical limit under normal conditions, with extensions farther north in high water. Downstream trips were much faster than upstream ones due to the current. The boat also made special recreational runs from Yuma or Needles to nearby points of interest or into the Gulf.

Overall, the Mohave II exemplified the height of Colorado River steamboating technology and commerce in the late 19th century—bridging the pre-railroad era of isolated desert Southwest settlement, mining, and military supply with the transition to rail dominance—while providing both essential transport and occasional community recreation on one of the West’s most difficult rivers.

Cochan – Colorado River Steamship

The Cochan was the last stern-wheel steamboat operated by the Colorado Steam Navigation Company (CSNC) on the Colorado River, running from late 1899/1900 until about 1909–1910. Named for the Quechan (Yuma) people, it marked the end of commercial steam navigation on the lower Colorado after nearly six decades of steamboat activity that began in 1852.

View showing steamboat Cochan on the Colorado River near Yuma, Arizona in 1900 - U.S. National Archives and Records Administration
View showing steamboat Cochan on the Colorado River near Yuma, Arizona in 1900 – U.S. National Archives and Records Administration

Origins and Construction

By 1899, CSNC owners Isaac Polhamus and Jack Mellon faced aging vessels and renewed competition from newer boats (including the St. Vallier). Their remaining steamers, the Mohave II (about 23 years old) and the Gila (launched 1873 and already more than 25 years in service), had worn hulls requiring heavy maintenance. The Gila was selected because it retained better engines.

In late 1899, the Gila’s machinery was refurbished and installed in a rebuilt (or heavily reconstructed) hull at the shipyard in Yuma, Arizona, at a cost of roughly $25,000 (some accounts cite about $27,000). The vessel was launched on November 8, 1899, and renamed Cochan. It was two tons lighter and 14 feet shorter than the Gila.

Key specifications:

  • Displacement: 234 tons
  • Length: 135 feet
  • Beam: 31 feet
  • Draft: 11 inches unloaded; less than 2 feet (about 22 inches) when loaded with cargo
  • Cargo capacity: up to 125 tons of freight
  • Propulsion: stern paddlewheel driven by the refurbished steam engines from the Gila

The Cochan was a classic Western-river sternwheeler optimized for the Colorado’s difficult conditions—shifting sandbars, snags, swift currents, seasonal low water, and abrasive sand. Design priorities emphasized extreme shallow draft, a relatively flat or lightly built wooden hull reinforced against grounding and impacts, and reliable (rather than high-speed) power for towing barges. Sternwheel configuration aided maneuverability in confined or shallow channels and allowed techniques such as using the wheel to help dig through bars. These principles continued the adaptations that Colorado River boats had developed since the 1850s, prioritizing flotation and cargo-carrying ability in minimal water over ocean-style seaworthiness or deep-draft efficiency.

In 1900 the company also built a new barge, the Silas J. Lewis (about 150 feet long and 32 feet in beam), for the Cochan to tow, while scrapping older barges.

Operations and Role in Trade

The Cochan entered service in January 1900, carrying freight to mining districts such as the Quartette and Searchlight mines in Nevada and competing directly with the St. Vallier (and later the Searchlight). It operated primarily on the lower Colorado between Yuma, Arizona, and points upstream toward Needles, California, and mining areas, supporting the final phase of the region’s mining boom with supplies, equipment, ore, and passengers.

Steamboats like the Cochan remained important for expanding and sustaining trade along the Colorado long after the Southern Pacific Railroad reached Yuma in 1877. They provided the most economical means of moving bulk goods across the desert Southwest until rail lines fully displaced them. The Cochan and its contemporaries hauled freight for mines, helped supply irrigation and reclamation projects (including work related to the Imperial Valley and the temporary diversion that formed the Salton Sea), and maintained local commerce on stretches of the river still poorly served by rail. By the early 1900s, however, additional rail bridges (including the Arizona and California Railroad at Parker in 1905) and the completion of Laguna Dam in 1909 (about 14 miles above Yuma) progressively eliminated upstream navigation. By the end of 1905 most boats, including the Cochan, had been withdrawn to the Yuma area.

Steamer "Cochan" on Colorado River at Needles. The Otis Marston Colorado River Collection. The Huntington Library, San Marino, California.
Steamer “Cochan” on Colorado River at Needles. The Otis Marston Colorado River Collection The Huntington Library, San Marino, California.

End of Service

Just before Laguna Dam closed the river to steam navigation, the CSNC sold its remaining boats, including the Cochan, to the U.S. Reclamation Service in 1909. The Service had no need for the vessel, and it was dismantled in the spring of 1910 at Yuma. This marked the practical end of the steamboat era on the lower Colorado, which had facilitated thousands of tons of annual commerce since the 1850s.

Historical Significance

The Cochan embodied the final refinement of shallow-draft sternwheeler design for one of North America’s most challenging rivers. By recycling proven engines into a lighter, shorter hull with exceptional draft performance, its builders extended the economic life of river transport during a period of intensifying competition from railroads and dams. It supported late mining activity, early 20th-century reclamation efforts, and residual trade until infrastructure changes rendered steamboats obsolete. As the last major sternwheeler of the Colorado Steam Navigation Company, the Cochan closes a chapter in the transportation history of the American Southwest that had opened the desert interior to sustained commercial development.

Searchlight – Colorado River Steamships

The Searchlight was the last sternwheel steamboat built for the lower Colorado River. It operated primarily from 1903 into the 1910s, serving the final phase of commercial steam navigation that had begun in 1852.

Construction and Specifications

The Searchlight was built in 1902 at Needles, California, by F. L. Hawley for the Colorado River Transportation Company. It was launched in December 1902; its engines were installed afterward, and it entered service on the river by March 1903.

Key recorded dimensions include:

  • Length: 91 feet
  • Beam: 18 feet
  • Tonnage: 98 tons
  • Type: Stern-wheel paddle steamer (sternwheeler)

Draft details specific to the Searchlight are not precisely recorded in available summaries, but Colorado River sternwheelers were characteristically shallow-draft vessels (often drawing well under 2 feet light and only modestly more when loaded). This was essential for the river’s shifting sandbars, variable seasonal flows, and sediment-laden channels.

It later passed through ownership by the Colorado Steam Navigation Company and the U.S. Reclamation Service. Sources describe it as “lost” in October 1916; it is widely regarded as the last paddle-wheeled commercial boat to operate on the lower river.

Design Principles

Colorado River steamboats, including the Searchlight, were purpose-built for one of North America’s most difficult navigable rivers. Core design principles included:

  • Sternwheel propulsion: A large paddlewheel at the stern provided better maneuverability in narrow, winding channels and over sandbars than sidewheels. It also reduced vulnerability to debris and allowed the boat to “walk” over obstacles more effectively in heavy, silty water.
  • Shallow draft and relatively light construction: Flat or lightly built wooden hulls minimized draft so vessels could operate in low water and cross bars that would ground deeper-draft craft. Cargo capacity was balanced against the need to remain afloat in only a foot or two of water when lightly loaded.
  • Practical freight focus: These boats prioritized utility over luxury. They carried mining equipment, supplies, ore, passengers, and towed barges. Interiors and superstructures were functional rather than ornate (in contrast to some larger Mississippi packets).
  • Adaptation to local conditions: Builders accounted for strong currents, extreme temperature swings, wood or other available fuel, and the need for frequent repairs in remote locations. The Searchlight, constructed on-site at Needles rather than shipped in sections from San Francisco (common for earlier boats), reflected the mature local capability for riverboat construction by the early 1900s.

These features made the vessels effective for the lower Colorado from the Gulf of California/delta region upstream past Yuma toward Needles and mining landings, even as the river’s character changed with seasonal floods and droughts.

Role in Expanding Trade

By the late 1890s and early 1900s, the lower Colorado’s steamboat trade had shifted heavily toward supporting mining booms after railroads had already captured much of the long-haul freight. Gold discoveries in the Searchlight District (Nevada, about 14 miles west of the river, south of Eldorado Canyon) in 1897, along with related activity at Quartette Landing and other camps, created renewed demand for river transport of machinery, supplies, food, and outbound ore.

The Searchlight was built specifically to compete in this traffic. It quickly cut into the Colorado Steam Navigation Company’s (CSNC) business to Quartette Landing and Searchlight, Nevada. Operating alongside rivals such as the Cochan (CSNC’s last major sternwheeler, rebuilt from the Gila and placed in service in 1900 for the same mining trade) and the St. Vallier, it helped sustain the final commercial pulse of river steam navigation.

Steamers of this era moved the materials that allowed remote desert mining camps to operate and expand. They linked river landings to overland trails and, later, short rail spurs (such as the Barnwell and Searchlight Railway). In doing so, they supported economic development in parts of present-day Nevada, Arizona, and California where roads remained difficult and expensive.

Competition from expanding rail networks (Southern Pacific earlier, then lines reaching Parker and other points) steadily eroded profitability. By the end of 1905 the remaining steamers, including the Searchlight, were largely withdrawn downriver to the Yuma area. Smaller gasoline boats and eventually trucks took over residual local work.

End of Service and Legacy

The 1909 completion of Laguna Dam (about 14 miles above Yuma) for irrigation effectively closed the lower river to through navigation. Remaining steamers, including the Searchlight, were used for limited reclamation, bank repair, canal-related work, and occasional local freight or ferry duties. The Searchlight is recorded as the last of the commercial paddlewheel fleet, finishing service around 1916.

Its historical significance lies in marking the close of an era. From the Uncle Sam in 1852 through the peak decades of the Colorado Steam Navigation Company and into the early 20th century, sternwheelers opened and sustained trade, military supply, settlement, and mining along a river that was otherwise extremely difficult to navigate. The Searchlight—the final new sternwheeler built for the lower Colorado—embodied the practical design adaptations that made that commerce possible and helped support the last major mining boom the river boats would serve.

Primary modern references for these details include Richard E. Lingenfelter’s Steamboats on the Colorado River, 1852–1916 and contemporary summaries drawn from period records and photographic collections (including images of the Searchlight at locations such as Chimney Peak, Needles, and Yuma).

Retta – Colorado River Steamship

The Retta was a small stern-wheel paddle steam launch that operated on the lower Colorado River in the early 20th century. It belonged to the final generation of commercial steam vessels on the river, during a period of declining steamboat traffic due to railroad expansion, yet still serving mining, local freight, and limited passenger needs. Steam navigation on the Colorado began in 1852 with the Uncle Sam to supply Fort Yuma and peaked under the Colorado Steam Navigation Company (CSNC, formerly George A. Johnson & Company). By 1900–1909, operations focused on residual mining traffic (e.g., Searchlight and related districts) until Laguna Dam blocked upstream navigation.

The Retta was one of the smaller craft in this late phase, operated primarily by the short-lived Mexican-Colorado Navigation Company.

Construction and Design Principles

Built in 1900 at Yuma, Arizona (by Captain Frank Friant according to detailed accounts), the Retta was an open-decked paddle-wheel steam launch approximately 36 feet long with a 6-foot beam. It featured a scalloped canopy. Exact draft, tonnage, and engine details are sparsely recorded, but it was designed as a light, maneuverable vessel rather than a heavy freighter.

Colorado River steamboats followed specific design principles dictated by the river’s extreme challenges: shallow depths (often under 2 feet in low water), shifting sandbars, strong currents, snags, abrasive silt, and seasonal floods. Key principles included:

  • Shallow draft — Priority for flotation over sandbars and in low water; larger sternwheelers often drew 12–22 inches loaded.
  • Stern-wheel (paddle) propulsion — Preferred over sidewheels for better maneuverability in narrow or braided channels, ability to “dig” through bars with the wheel, and reduced risk of damage in confined waters.
  • Lightweight wooden construction — Flat or lightly framed hulls optimized for cargo capacity relative to draft, with reinforcement against grounding; many larger boats were built in sections in San Francisco, shipped, and reassembled at the river (e.g., Port Isabel or Yuma).
  • Practical, utilitarian layout — Focus on freight/tow capacity and reliability over speed or luxury; fuel from local mesquite/cottonwood woodyards.
  • Adaptability for towing — Larger vessels often towed barges to multiply capacity.

The Retta, as a compact steam launch, embodied a scaled-down version of these principles: extreme lightness and shallow operation for local upriver work in variable conditions, suited to light freight rather than bulk cargo or long tows. It was originally built for pleasure excursions before commercial use.

Ownership, Operations, and Role in Expanding Trade

The Mexican-Colorado Navigation Company (formed ~1901 in Los Angeles by Alphonso B. Smith with Chicago investors W. S. Twogood and E. E. Busby) acquired the Retta (sources note purchase around July or December 1901) as part of its fleet, which also included the larger sternwheeler St. Vallier (acquired late 1901) and the screw steamer San Jorge. The company aimed to revive river traffic for mining, ranching, and irrigation support, operating from Yuma and competing with the CSNC on routes to Needles and intermediate points, plus limited Gulf of California service.

The Retta handled light freight on upriver runs to landings such as Ehrenberg and Picacho. By fall 1901 it carried items including railroad rails and saw “brisk business.” In early 1905 it was sold to F. C. Robie and William Hutt of Needles, who overhauled it for freighting between Mellen (near Topock) and the Bill Williams Fork mining settlements.

Its role in expanding (or sustaining) trade was modest and localized compared to the big CSNC sternwheelers (Gila, Mohave II, Cochan, etc.) that had earlier enabled major mining booms, military supply, and settlement by linking Pacific ports to interior Arizona, Nevada, and Mexican territories via the river mouth. In the post-railroad era, the Retta and similar small craft filled gaps for short-haul mining supplies, ore, and materials where rail did not yet fully penetrate, supporting residual economic activity along the lower river and its tributaries until dams and further rail closed the era. Overall Colorado River steamboating had already shifted from primary artery of regional development (1850s–1870s) to supplementary service.

Fate

In February 1905 the Retta struck a submerged log (or rock in some accounts) and sank. Its commercial career lasted only about five years.

Legacy

The Retta represents the tail end of Colorado River steam navigation—a practical, small-scale vessel adapted to the river’s demanding conditions during the industry’s decline. Larger boats had transformed Southwest logistics; vessels like the Retta extended limited utility for mining trade a few years longer. Primary sources for this history include Richard E. Lingenfelter’s Steamboats on the Colorado River, 1852–1916 (University of Arizona Press, 1978), the standard reference documenting the fleet, companies, and operations.