North Platte


From Wyoming Tales and Trails

This page: Pathfinder Dam and Reservoir.

Big Horn Basin Black Hills Bone Wars Buffalo Cambria Casper Cattle Drives Centennial Cheyenne Chugwater Coal Camps Cody G. A. Custer Deadwood Stage Douglas Dubois Encampment Evanston Ft. Bridger Ft. Fetterman Ft. Laramie Ft. Russell Frontier Days Ghost Towns Gillette G. River F. V. Hayden Tom Horn Jackson Johnson County War Kemmerer Lander Laramie Lincoln Highway Lusk Meeteetse Medicine Bow N. Platte Valley Oil Camps Overland Stage Pacific Railroad Rawlins Rock Springs Rudefeha Mine Sheepherding Sheridan Shoshoni Superior Thermopolis USS Wyoming Wheatland Wild Bunch Yellowstone

Table of Contents
About This Site

Dam Keepers House, Pathfinder Dam, 1906

Portions of the North Platte are among the most modified of the rivers of the west. Seven dams create reservoirs along its course, the Seminoe, photo below, and Kortes dams upstream from the Pathfinder Reservoir and the Alcova, Gray Reef, Glendo and Guernsey downstream.

Pathfinder Dam, 1922

The oldest of the dams is the Pathfinder located about 45 miles southwest of Casper at the confluence with the Sweetwater. The dam, one of the first constructed by the Reclamation Service, was started in 1905 and completed in 1909. Difficulties were experienced in construction including even obtaining a contractor. The first bidder, Bradbury & O'Gara of Denver withdrew their bid after reviewing local conditions. The next bidder N.S. Sherman of Oklahoma City did not have the financial ability to carry out the project. Ultimately, the contract was awarded to Geddis and Seerie Stone Co. of Denver for $428,000. With cost overruns, however, the project cost climbed to $626,523.52. Other projects undertaken by the firm included the Colorado State House, the Brown Palace Hotel, the Omaha Post Office and the Cheesman Dam which provided water for Denver. The diversion tunnel carrying the river around the dam site and ultimately serving as the outlet for the reservoir was constructed by Kilpatrick Brothers and Collins Contracting Company.

Freight wagons hauling supplies to Pathfinder Dam.

Difficulties of construction on the Pathfinder Dam included merely getting materials to the site. Concrete had to be brought by freighter from Casper. There it cost an average of $2.68 a barrel. Transportation to the dam site cost an additional $3.00 a barrel and took anywhere from three days to over two months to traverse the distance from Casper. All kinds of freighters were used to bring the materials to the dam, from a 22-horse team drawing five wagons carrying 31,000 pounds of cement to a two-horse sheep wagon.

Freight wagons hauling cement to Pathfinder Dam, 1907.

The site lacked coal for the steam engines powering the machinery. Kilpatrick Brothers had used all local timber as fuel for their machinery. Thus, cord wood was cut in the Pedro Mountains ten miles to the south and hauled to the site. The difficulties of transportation were such that at the conclusion of construction much of the equipment was abandoned as not being worth the cost to get it back to Denver.

Pathfinder Spillway approx. 1920

The weather was of little help in the construction of the Pathfinder. Initial excavation to bedrock was delayed while crews cut through ice as much as three feet thick in temperatures as low as -29 F., followed in the spring by flooding. Thus, the first stones of the masonry structure were not laid until August of 1906. Indeed, the weather had its final revenge in 1909. During the last month of construction the weather again took its toll, alternating between cold, rain and wind.

Seminoe Dam, constructed 1936-1939

The Pathfinder Dam originally held promise for irrigation. However, in 1912, the State Engineer, A. J. Parshall, complained that although the original intent of the project was to provide irrigation for 700,000 acres, most of which was to be in Wyoming, the vast majority of the area actually irrigated was in Nebraska. He continued by noting that, excluding some 17,000 acres belonging to the North Platte Canal and Colonization Company, only 4,000 acres had been reclaimed in the state, "a very small area to reclaim after submerging 22,000 acres * * * * [a large part of which] was improved and irrigated land * * *."

The Seminoe Dam, 31 miles northeast of Rawlins, was constructed between 1936 and 1939. The reservoir provides hydro-electric power and water for irrigation, with water being released as necessary to the Pathfinder downstream. As with the Pathfinder, weather still provides problems. Freeze-thaw has caused cracking in the concrete structure requiring refurbishment and monitoring. Access to the power plant is on occassion obstructed by rockslides in the narrow canyon also requiring maintainance and extra expense.

The name "Seminoe" is an Anglicizing of Cimineau. The Seminoe Mountains and Reservoir are named after Basil Cimineau LaJeunesse, a French-Louisianan guide who accompanied each of the three Fremont expeditions including the 1843 expedition along the Platte and Sweetwater. LaJeunesse was killed by Klamath Indians in May, 1846, near Klamath Lake, Oregon. The name was applied first to the area by LaJeunesse's brother, Charles LaJeunesse.

Seminoe Dam under construction, 1936.

Next Page, Bessemer.