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33-507: Pathfinder Dam is composed of granite blocks, quarried from the same stone that forms the river's canyon. With Buffalo Bill Dam , its contemporary, Pathfinder Dam was intended to irrigate semi-arid lands in Wyoming. Buffalo Bill Dam is of concrete construction, owing to its location within 7 miles (11 km) from the railroad, while Pathfinder Dam is about 45 miles (72 km) from the nearest railroad. Freight took at least three days to cover

66-403: A 1995 proposal to add between 2 feet (61 cm) and 2.5 feet (76 cm) to the top of the dam to add storage capacity. The Pathfinder Interpretive Center is a small museum located in the former damkeeper's residence near the dam. Pathfinder National Wildlife Refuge encompasses portions of the reservoir. There are five campgrounds and a marina on the reservoir. A suspension footbridge crosses

99-538: A 2.8-mile (4.5 km) irrigation tunnel completed in 1939. The dam is located in Shoshone Canyon, and named after the famous Wild West figure William "Buffalo Bill" Cody , who founded the nearby town of Cody and owned much of the land now covered by the reservoir formed by its construction. It is part of the Shoshone Project , successor to several visionary schemes promoted by Cody to irrigate

132-401: A byproduct. The unit operates a Francis turbine generating 4.5 MW on a seasonal base load basis, with a 110-foot (34 m) head. It was built in 1994. Arch-gravity dam An arch-gravity dam or arched dam is a dam with the characteristics of both an arch dam and a gravity dam . It is a dam that curves upstream in a narrowing curve that directs most of the water pressure against

165-486: A contract for a 480-foot (150 m) long diversion tunnel was let in 1905. Bidding for the dam construction contract was plagued with delays. The initial contractor withdrew, citing bidding errors. Eventually, the construction contract was awarded to the Geddis and Seerie Stone Company of Denver, for an initial sum of $ 482,000, later rising to $ 626,523.52. Difficulties with the construction of an upstream cofferdam, created by

198-471: A diversion dam, which was to divert the river into a wooden flume , through a tunnel and out through another flume to rejoin the river bed. Two men were killed in the construction of the tunnel. A June 1906 flood destroyed the flume. The delay caused the Bureau of Reclamation to suspend the contractor's contract and to call upon the contractor's bonding company, the U.S. Fidelity and Guaranty Company , to ensure

231-517: A final cost of $ 1.4 million. Seven construction workers were killed on the project. Immediately after completion the dam suffered from leakage through the outlet works, leading to low water elevations that exposed mudflats, which soon produced dense blowing dust. Corrective work to valves took until 1915. Problems with the north abutment's outlet works (on the right, facing the dam from downstream) led to their abandonment in 1959. They were sealed in 1961. The reservoir began to lose capacity immediately as

264-542: A high-gas environment. Work on the tunnel by the Utah Construction Company was complete in 1939. The Heart Mountain Powerplant was built at the tunnel's outlet in 1947 as a temporary facility. It was rebuilt concurrently with the dam heightening project and is operated on a seasonal basis. It operates a 5 MW Francis turbine on a 265-foot (81 m) head. Starting in 1985, the crest of the dam

297-476: A result of the Shoshone's heavy silt load, and the material deposited at the head of the reservoir continued to blow when the reservoir was drawn down. Work continued on silt dikes and reforestation into the 1950s, but capacity is reduced from the reservoir's nominal capacity of 869,230 acre-feet (1.07218 km ) to 623,557 acre-feet (0.769146 km ) due to siltation. The new reservoir covered hot springs at

330-445: A suitable elevation for distribution. Work on the 2.8-mile (4.5 km) Shoshone Canyon Tunnel started in 1937, accompanied by the death of two tunnel workers who were overcome by fumes from explosives and hydrogen sulfide from nearby geothermal activity, and were subsequently struck by construction equipment. A natural cave had to be crossed by a concrete flume of two 70 feet (21 m) spans, constructed under difficult conditions in

363-470: Is an example of the RCC arch-gravity dam. A gravity dam requires a large volume of internal fill. An arch-gravity dam can be thinner than the pure gravity dam and requires less internal fill. Arch-gravity dams are dams that resist the thrust of water by their weight using the force of gravity and the arch action . An arch-gravity dam incorporates the arch 's curved design which is effective in supporting

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396-479: The American Society of Civil Engineers in 1973. The land around the reservoir is maintained as Buffalo Bill State Park . The dam is a concrete arch-gravity dam , 70 feet (21 m) wide at the base and 200 feet (61 m) wide at the crest, with an original height of 325 feet (99 m), extended 25 feet (7.6 m) between 1985 and 1992. The concrete structure measures 108 feet (33 m) deep at

429-568: The Bighorn Basin and turn it from a semi-arid sagebrush-covered plain to productive agricultural land. Known at the time of its construction as Shoshone Dam , it was renamed in 1946 to honor Cody. The original structure was designed by engineer Daniel Webster Cole and built between 1905 and 1910. It was listed on the National Register of Historic Places in 1971 and named a National Historic Civil Engineering Landmark by

462-468: The canyon rock walls, providing the force to compress the dam. It combines the strengths of two common dam forms and is considered a compromise between the two. They are made of conventional concrete , roller-compacted concrete (RCC), or masonry . Arch-gravity dams are not reinforced except at the spillway . A typical example of the conventional concrete dam is the Hoover Dam . Changuinola Dam

495-403: The base, tapering to 10 feet (3.0 m) at the crest, with a volume of 82,900 cubic yards (63,400 m ) of concrete. It is anchored into Pre-Cambrian granitic rock on either side. The spillway is an uncontrolled overflow weir on the south side, 298 feet (91 m) wide, dropping through a tunnel in the south abutment. The first of four full-time and seasonal power generation facilities

528-610: The completion of the work. Little work was done until March 1907. Another flood in July damaged the diversion dam again. Working conditions were harsh, leading to the first strike in Wyoming's history in November, in which workers demanded and received three dollars a day from USF&G. USF&G delegated responsibility for the work to two new contractors, Locher and Grant Smith and Company, in March 1908. Work progressed more quickly, with

561-551: The construction of one of the first high concrete dams in the United States. Work began immediately, with drilling for geologic investigation starting in July 1904 and continuing for ten months. Work proceeded concurrently on the construction of an access road up the narrow canyon from Cody. The chosen contractor, Prendergast & Clarkson of Chicago, started work in September 1905, building a camp for workers and starting on

594-470: The contractor's improper blasting of loose rock from the canyon walls, led to the first delays. Foundation work on the dam started in January 1906, with the foundation set only 10 feet (3.0 m) deep. After delays caused by flood waters, the dam was completed on June 14, 1909. Unusual summer rains filled the reservoir, overtaxed the spillways and threatened to overtop the unfinished auxiliary dike south of

627-716: The dam and the powerplant. In 1902 plans were advanced to dam the Sweetwater River at a narrow point known as Devil's Gate. A more ambitious plan was proposed in 1903 by the newly established Bureau of Reclamation to dam a site below the confluence of the Sweetwater and the North Platte. The dam's design was carried out by George Y. Wisner of the Reclamation Service, with consulting engineer Edgar T. Wheeler. Exploratory drilling began in 1903, and

660-411: The dam, possibly allowing the river to cut a new, lower channel and potentially leaving the damsite dry. Explosive charges were placed in the crest of the main dam to be used if the overflow occurred, thus keeping the lowest point at the dam. The dike held and the charges were not needed, but did have to be removed by explosives experts in 1949. An auxiliary dike was built at the location in 1910 to develop

693-555: The dam. Buffalo Bill Dam Buffalo Bill Dam is a concrete arch-gravity dam on the Shoshone River in the U.S. state of Wyoming . Originally 325-foot (99 m), it was the tallest dam in the world when it opened in 1910; a 25-foot (7.6 m) extension was added in 1992 in one of numerous changes and improvements to the structure and its support facilities, which include two full time power generators and two seasonal operations added between 1920 and 1994, and

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726-454: The distance, and once took 76 days. Transportation of cement in barrels was not feasible by horse-drawn wagon, so the dam was built of quarried stone. The dam was faced with stones between 24 inches (61 cm) and 36 inches (91 cm) thick, laid in a 2-inch (5.1 cm) thick mortar bed. Between these facings was a core of irregularly-shaped granite blocks of up to ten tons in weight, bedded in mortar and quarry tailings. The diversion tunnel

759-457: The first concrete pours in April. Spring floods set the project back once again, causing concrete work to be suspended. Concrete work started again in March 1909, and despite more spring flooding that suspended work from July to September, work moved quickly. Another threatened strike was broken when Italian laborers were replaced with Bulgarian workers. Final concrete was poured in January 1910, with

792-578: The forks of the Shoshone, similar to those found at Colter's Hell at the mouth of the Shoshone Canyon. Work on the Shoshone Power Plant started in 1920. The power plant is located 600 feet (180 m) downstream from the dam on the north side of the canyon. Following delays for spring flooding, work on the power house and supply tunnel was complete in 1922, ready for the installation of electrical equipment. Generating units 1 and 2 came on line in 1922, with Unit 3 in 1931. Installed capacity

825-680: The reservoir's full capacity. The potential overtopping gave rise to sensational stories in Denver newspapers and caused annual nervousness in Casper downstream for a number of years thereafter. The Fremont Canyon Powerplant was built between 1958 and 1961, part of the Glendo Unit of the Pick–Sloan Missouri Basin Project . The reservoir has suffered from sedimentation, as all dams do, which leads to reduced capacity and leading to

858-412: The river below the dam. Pathfinder Dam was placed on the National Register of Historic Places on August 12, 1971. In 2015, the dam was included in a historic district encompassing the dam itself, its operating facilities, and the archaeological remains of its construction camp. The reservoir has overflowed in 1984, 2010 and 2011, and 2016 with overflow water forcing a channel to the immediate north of

891-491: The tunnel was modified to feed the power outlet works, an 18 feet (5.5 m) tunnel extending 3 miles (4.8 km) to the Fremont Canyon Powerplant at the upper end of Alcova Reservoir . The Fremont Canyon Powerplant has a capacity of 66.8 MW with two turbines, upgraded from 48 MW between 1986 and 1990. A low-flow outlet was completed at the dam in 1997 to allow water flow in the four river miles between

924-450: The water in narrow, rocky locations where the gorge 's sides are of hard rock and the water is forced into a narrow channel. Therefore, the span needed for the dam is also relatively narrow, and the dam's curved design effectively holds the water back while using less construction material compared to a pure arch dam or gravity dam. These dams are more reliable than arch dams. Typically, arch-gravity dams are built in canyon-like terrain, with

957-491: Was 6.012 MW. All three units were shut down in 1980, worn out from fifty years of service. 1 and 2 were decommissioned and left in place, while 3 was replaced with a new 3 MW Francis turbine unit that started operation in 1992. The plant operates with a head of 220 feet (67 m). The proposed Heart Mountain Canal project, intended to irrigate lands to the north of the river, required a new tunnel to direct irrigation waters to

990-453: Was adapted to become the dam's outlet works. Construction costs were $ 2.5 million in 1909. An auxiliary dike, 38 feet (12 m) high, extends to the south of the dam. It is an earthfill structure with a concrete corewall. A natural channel was enlarged and straightened to form an uncontrolled spillway on the north side of the dam. The original diversion tunnel became the north outlet works, abandoned and sealed in 1958 with bulkheads. From 1958

1023-462: Was added in 1922. The Heart Mountain Canal Project, which brings water to irrigate lands to the north of the river, required the construction of the 2.8-mile (4.5 km) Shoshone Canyon Tunnel, completed in 1939. With the authorization of the Shoshone Project in 1904, Buffalo Bill Dam became one of the earliest projects of the new Bureau of Reclamation . The ambitious project involved

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1056-461: Was built concurrently with the work to increase the dam's height in 1992. The plant, located in Shoshone Canyon downstream from the original Shoshone Powerplant, operates three Francis turbines with generators rated at 6 MW each on a head of 266 feet (81 m). The Spirit Mountain Powerplant receives pressurized water through a conduit. It primarily functions to dissipate the pressure in the conduit before it enters an open canal, generating power as

1089-551: Was raised 25 feet (7.6 m), increasing the reservoir's capacity by 260,000 acre-feet (0.32 km ) when the project was completed in 1993. The spillways were enlarged and equipped with radial arm gates. The project also included a visitor center, located at the north end of the dam's crest. The additional height allowed 25.5 MW of additional generating capacity to be added to the project. The expanded reservoir inundated facilities at Buffalo Bill State Park, requiring their relocation and reconstruction. The Buffalo Bill Power Plant

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