General

• Vicinity Map
• Region (Map) ....................... Great Plains
• State (Map) ............................... Montana
• County ....................................... Big Horn
• Project ........................ PSMBP-Yellowtail
• Dam type ................. Concrete thick arch
• Location .......... 45 mi SW of Hardin, MT
• Watercourse ..................... Bighorn River
• Reservoir ............................ Bighorn Lake
• Original construction .............. 1961-1966
• Modified ............................................ 1968
• National ID Number ................. MT00576
• Hydrologic Unit Code ..................

Hydraulics

• Total storage to
    El. 3660 ......................... 1,427,840 acre-ft
• Service spillway
    Capacity at El. 3660 ............... 92,000 cfs
• Irrigation outlet works
    Capacity at El. 3640 ................. 3,970 cfs
• Evacuation outlet works
    Capacity at El. 3640 .................. 4,090 cfs

Dimensions

• Crest Elevation .............................. 3660.0 ft
• Structural Height ................................ 525 ft
• Hydraulic Height ................................ 474 ft
• Crest Length ..................................... 1,480 ft
• Crest Width ........................................... 22 ft
• Base Width ......................................... 147 ft
• Volume of Concrete .......... 1,545,664 cu yd

Hydrology

• Drainage area .......................... 19,650 sq mi
• Hydrometeorological Report ............... NA
• PMF .............................. 1988 Rain on snow
• Volume .. 4,700,000 acre-ft over 18.75 days
• Peak inflow ................................. 887,000 cfs
• Maximum water surface ................ 3689.1 ft