Pathfinder Dam facts for kids
Quick facts for kids Pathfinder Dam |
|
|---|---|
Pathfinder Dam
|
|
| Location | Natrona County, Wyoming, USA |
| Coordinates | 42°28′05″N 106°51′14″W / 42.46806°N 106.85389°W |
| Construction began | 1905 |
| Opening date | 1909 |
| Operator(s) | U.S. Bureau of Reclamation |
| Dam and spillways | |
| Type of dam | Cyclopean masonry gravity arch |
| Impounds | North Platte River |
| Height | 214 feet (65 m) |
| Length | 432 feet (132 m) |
| Width (crest) | 10.5 feet (3.2 m) |
| Width (base) | 96.5 feet (29.4 m) |
| Dam volume | 65,700 cu yd (50,200 m3) |
| Spillway type | Uncontrolled natural channel |
| Spillway capacity | 33,940 cu ft/s (961 m3/s) |
| Reservoir | |
| Creates | Pathfinder Reservoir |
| Total capacity | 1,016,500 acre-feet (1.2538 km3) |
| Catchment area | 14,600 sq mi (38,000 km2) |
| Power station | |
| Hydraulic head | 300 ft (91 m) |
| Turbines | 2 x 33.4 MW Francis-type at Fremont Canyon Powerplant |
| Installed capacity | 66.8 MW |
| Annual generation | 172,606,300 KWh (2007) |
|
Pathfinder Dam
|
|
| NRHP reference No. | 71000888 |
| Added to NRHP | August 12, 1971 |
The Pathfinder Dam is a large dam made of stone. It's located on the North Platte River in Wyoming, about 47 miles (76 km) southwest of Casper. It was built between 1905 and 1909 as part of the North Platte Project. This project helped bring water to farms.
The dam has been updated many times since it was first built. It is now listed on the National Register of Historic Places, which means it's an important historical site. The dam created Pathfinder Reservoir, a huge lake that stores water. This water helps irrigate over 226,000 acres (915 km2) of farmland in Wyoming and Nebraska. The dam is named after General John C. Frémont, who explored the area in 1842. He was known as the "Pathfinder of the West."
Contents
How Pathfinder Dam Was Built
The Pathfinder Dam is made from large granite blocks. These stones were dug up from the same canyon where the river flows. At the time, the Pathfinder Dam and the Buffalo Bill Dam were both built to bring water to dry lands in Wyoming.
Building with Stone Instead of Concrete
The Buffalo Bill Dam was built with concrete because it was close to a railroad. This made it easy to bring in cement. But the Pathfinder Dam was about 45 miles (72 km) from the nearest railroad. It took at least three days to transport materials by horse-drawn wagons. Sometimes it even took 76 days! Because it was so hard to move cement barrels, the dam was built using quarried stone instead.
Dam Construction Details
The outside of the dam was covered with stones that were 24 to 36 inches (61 to 91 cm) thick. These stones were laid in a 2-inch (5 cm) thick layer of mortar. Inside, the dam was filled with granite blocks of different shapes, some weighing up to ten tons. These huge blocks were also set in mortar and leftover quarry materials.
The original tunnel used to divert the river during construction was later changed. It became the dam's main water outlet. The total cost to build the dam was $2.5 million in 1909.
Spillway and Dike
An extra dike, which is like a small wall, was built south of the dam. It is 38 feet (12 m) high and made of earth with a concrete wall inside. A natural channel on the north side of the dam was made wider and straighter to create a spillway. This spillway lets extra water flow out when the reservoir is too full.
Dam Operations and Power Generation
The first tunnel used to divert the river was sealed off in 1958. After that, it was changed to send water to the Fremont Canyon Powerplant. This powerplant is about 3 miles (5 km) away, near the Alcova Reservoir.
Fremont Canyon Powerplant
The Fremont Canyon Powerplant has two large turbines. It can produce 66.8 megawatts (MW) of electricity. This power plant was upgraded between 1986 and 1990 to make more electricity. In 1997, a special outlet was added at the dam. This allows a small amount of water to flow into the river between the dam and the power plant.
History of Pathfinder Dam
Plans to build a dam in this area started in 1902. The Bureau of Reclamation proposed a bigger plan in 1903 to dam the North Platte River.
Early Construction Challenges
Engineers started drilling to explore the site in 1903. A contract for a 480-foot (146 m) long tunnel was given out in 1905. The first company hired to build the dam backed out. They said they made mistakes in their bid. Finally, the Geddis and Seerie Stone Company of Denver got the contract. The cost started at $482,000 but grew to over $626,000.
There were also problems with building a temporary dam upstream. The contractor blasted rocks from the canyon walls, which caused delays. The foundation work for the dam began in January 1906. The foundation was set only 10 feet (3 m) deep.
Completion and Reservoir Filling
The dam was finished on June 14, 1909. However, unusual summer rains quickly filled the reservoir. The water almost went over the top of the unfinished dike south of the dam. If it had, the river might have cut a new path, leaving the dam useless. Explosives were placed on the main dam just in case, but they weren't needed. The dike held strong! These explosives were safely removed in 1949. An extra dike was built in 1910 to make sure the reservoir could hold its full amount of water.
Modern Updates and Uses
Like all dams, the Pathfinder Reservoir has collected sediment over time. This means it can't hold as much water as it used to. In 1995, there was a plan to make the dam a little taller to increase its storage capacity.
The Pathfinder Dam is also a place for learning and recreation. The Pathfinder Interpretive Center is a small museum in the old damkeeper's house. The Pathfinder National Wildlife Refuge includes parts of the reservoir. There are five campgrounds and a marina for boats. A suspension footbridge crosses the river below the dam.
The Pathfinder Dam was added to the National Register of Historic Places in 1971. In 2015, the dam and its surrounding areas, including the old construction camp, became part of a historic district.
Recent Overflows
The reservoir has overflowed several times, including in 1984, 2010, 2011, and 2016. When it overflows, the water creates a channel right next to the dam.
Images for kids
-
Pathfinder Dam spillway in June 2010
