Overview
Clark Canyon Dam is constructed at the head of the Beaverhead River. The zoned earthfill dam has a structural height of 147.5 feet, a crest length of 2,950 feet, and a volume of 1,970,000 cubic yards of material. The spillway consists of an approach channel, concrete inlet channel, ungated concrete crest, concrete chute, concrete stilling basin, and an outlet channel. The outlet works consists of an approach channel; concrete intake structure; concrete conduit; a gate chamber with high-pressure gates, two of which serve for emergency ahead of the regulating gates; concrete access shaft and shaft house; and a concrete stilling basin. The outlet channel is shared by the outlet works and spillway.
General
| Project | East Bench Unit, Pick-Sloan Missouri Basin Program |
| Dam Type | Zoned earthfill |
| Location | Twenty miles southwest of Dillon, Montana at the head of Beaverhead River in southwestern Montana. |
| Longitude | -112.85834312438965 |
| Latitude | 45.000415406254376 |
| Watercourse | Beaverhead River |
| Reservoir | Clark Canyon |
| Original Construction | 1961-1964 |
| Modified Construction | 1984: Tile toe drains were replaced and new drain field was constructed. |
| National ID Number | MT00569 |
| Crest Elevation | 5,578.00 ft |
| Structural Height | 147.50 ft |
| Hydraulic Height (Normal Operating Depth at Dam) | 113.90 ft |
| Crest Length | 2,950.00 ft |
| Crest Width | 36.00 ft |
| Top of Joint Use Pool (Elevation) | 5,546.10 ft |
| Top of Active Conservation Pool (Elevation) | 5,535.70 ft |
| Top of Inactive Conservation Pool (Elevation) | 5,470.60 ft |
| Base Width | 800.00 ft |
| Volume of Dam Construction Materials | 1,970,000.00 cu yds |
| Spillway Crest Elevation | 5,560.40 ft |
| Top of Dead Storage Pool (Elevation) | 5,455.00 ft |
| Spillway Type | Uncontrolled concrete crest and concrete-lined chute at left abutment |
| Spillway Capacity at Elevation | 9,520.00 cfs at 5,571.90 ft |
| Outlet Works Capacity at Elevation | 2,325.00 cfs at 5,547.00 ft |
| Maximum Water Surface Elevation | 325,324 acre-ft at 5,571.90 ft |
| Total Water Storage at Elevation | 257,152.00 acre-ft at 5,560.40 ft |
Contact
