Dams in Montana

2,986 damsAvg age: 74 years

190

High Hazard

192

Significant

2,602

Low Hazard

Dam Safety in Montana

Montana has 2,986 dams tracked in the National Inventory of Dams. Of these, 190 (6%) are classified as high hazard — meaning failure would probably cause loss of human life — and 192 are classified as significant hazard. Currently, 132 dams in the state have a condition assessment of poor or unsatisfactory, indicating recognized safety deficiencies.

The average dam in Montana is 74 years old. As dams age, inspection frequency and maintenance become increasingly important for ensuring public safety. The most common purpose for dams in Montana is fire protection, stock, or small fish pond, accounting for 1,829 of the state's dams.

The federal inventory is not every dam in Montana. It includes dams rated high or significant hazard, plus low-hazard dams above a size threshold (taller than 25 feet holding more than 15 acre-feet, or taller than 6 feet holding more than 50 acre-feet). Small, older dams below that line are usually left out, even though they can still shape the streams around them. The state's own dam safety program often tracks many more, and it is the agency that inspects most of them.

Use the search above to find dams near any address in Montana, or browse by county below. Each dam listing includes its hazard potential classification, condition assessment, physical characteristics, and inspection history from the NID.

Montana Dam Facts

Total Dams	2,986
High Hazard Dams	190
Average Dam Age	74 years
Tallest Dam	570 ft
Largest Reservoir	19,100,000 acre-ft
Poor/Unsatisfactory Condition	132

Notable Dams in Montana

Yankee Doodle Tailings Dam570 ftHigh Hungry Horse Dam564 ftHigh Yellowtail Dam525 ftHigh Libby Dam422 ftHigh Noxon Rapids260 ftHigh

Explore Montana Dams

Oldest DamsEarliest dams in Montana Tallest DamsHighest dams in Montana

Counties in Montana

Beaverhead44 dams7 high hazard Big Horn72 dams4 high hazard Blaine122 dams3 high hazard Broadwater5 dams1 high hazard Carbon15 dams4 high hazard Carter111 dams Cascade43 dams5 high hazard Chouteau103 dams Custer176 dams Daniels20 dams Dawson64 dams1 high hazard Deer Lodge11 dams3 high hazard Fallon36 dams2 high hazard Fergus109 dams4 high hazard Flathead12 dams8 high hazard Gallatin9 dams4 high hazard Garfield244 dams Glacier17 dams3 high hazard Golden Valley8 dams Granite11 dams2 high hazard Hill105 dams8 high hazard Jefferson11 dams7 high hazard Judith Basin20 dams2 high hazard Lake18 dams9 high hazard Lewis and Clark30 dams11 high hazard Liberty37 dams1 high hazard Lincoln19 dams6 high hazard Madison29 dams11 high hazard McCone120 dams1 high hazard Meagher49 dams8 high hazard Missoula22 dams6 high hazard Musselshell30 dams1 high hazard Park23 dams3 high hazard Petroleum55 dams5 high hazard Phillips174 dams3 high hazard Pondera43 dams4 high hazard Powder River47 dams Powell37 dams8 high hazard Prairie49 dams Ravalli21 dams9 high hazard Richland78 dams1 high hazard Roosevelt39 dams Rosebud270 dams4 high hazard Sanders8 dams3 high hazard Sheridan24 dams1 high hazard Silver Bow10 dams3 high hazard Stillwater10 dams3 high hazard Sweet Grass18 dams4 high hazard Teton38 dams6 high hazard Toole87 dams2 high hazard Treasure16 dams Valley144 dams Wheatland35 dams8 high hazard Wibaux13 dams Yellowstone25 dams1 high hazard

High Hazard Dams in Montana

Dam	County	Height	Condition	Purpose
Yankee Doodle Tailings Dam	Silver Bow	570 ft	Satisfactory	Other
Hungry Horse Dam	Flathead	564 ft	Not assessed	Flood Risk Reduction
Yellowtail Dam	Big Horn	525 ft	Not assessed
Libby Dam	Lincoln	422 ft	Not assessed	Hydroelectric
Noxon Rapids	Sanders	260 ft	Fair	Hydroelectric
Fort Peck Dam	McCone	256 ft	Not assessed	Flood Risk Reduction
Canyon Ferry Dam	Lewis and Clark	225 ft	Not assessed	Flood Risk Reduction
Swift (pondera)	Pondera	205 ft	Satisfactory	Irrigation
Selis Ksanka Qlispe (skq)	Lake	200 ft	Fair	Hydroelectric
Gibson Dam	Teton	199 ft	Not assessed	Irrigation
Kootenai Dvlpmnt Impoundment Dam	Lincoln	151 ft	Poor	Other
Clark Canyon Dam	Beaverhead	148 ft	Not assessed	Flood Risk Reduction
West Fork Bitterroot (painted Rocks)	Ravalli	143 ft	Poor	Irrigation
Willow Creek	Big Horn	136 ft	Fair	Irrigation
Sun River Diversion Dam	Teton	132 ft	Not assessed	Irrigation
Newlan Creek Dam	Meagher	131 ft	Poor	Irrigation
Hubbart	Flathead	130 ft	Poor	Irrigation
Hauser Dam	Lewis and Clark	125 ft	Satisfactory	Hydroelectric
Holter Dam	Lewis and Clark	124 ft	Satisfactory	Hydroelectric
Hebgen Dam	Gallatin	120 ft	Satisfactory	Hydroelectric
Ruby Dam	Madison	111 ft	Satisfactory	Irrigation
Fresno Dam	Hill	111 ft	Not assessed	Irrigation
Lake Sherburne Dam	Glacier	109 ft	Not assessed	Irrigation
Beaver Creek Reservoir Dam	Hill	108 ft	Fair	Irrigation
Morony	Cascade	107 ft	Satisfactory	Hydroelectric
Bair	Meagher	106 ft	Satisfactory	Irrigation
Nevada Creek Dam	Powell	105 ft	Satisfactory	Irrigation
Cochrane	Cascade	105 ft	Fair	Hydroelectric
Willow Creek Dam	Madison	105 ft	Poor	Irrigation
Cooney	Carbon	102 ft	Poor	Irrigation
Basin Creek Dam #1	Silver Bow	101 ft	Satisfactory	Water Supply
Crow	Lake	99 ft	Poor	Irrigation
Mission	Lake	98 ft	Fair	Irrigation
Lower Willow Creek Dam	Granite	96 ft	Poor	Irrigation
Tongue River Dam	Big Horn	93 ft	Satisfactory	Irrigation
Cedar Creek	Flathead	93 ft	Satisfactory	Water Supply
East Fork Dam	Fergus	93 ft	Satisfactory	Recreation
Martinsdale, North Dam	Wheatland	91 ft	Satisfactory	Irrigation
North Fork of Smith River Dam	Meagher	91 ft	Satisfactory	Irrigation
Colstrip Evaporation Pond Dam	Rosebud	88 ft	Satisfactory	Other
Bullhook Dam	Hill	87 ft	Satisfactory	Flood Risk Reduction
Ryan	Cascade	82 ft	Satisfactory	Hydroelectric
Pike Creek Dam	Fergus	81 ft	Satisfactory	Recreation
Cataract Creek Dam	Madison	80 ft	Unsatisfactory	Irrigation
Box Elder Creek Dam	Sheridan	80 ft	Satisfactory	Recreation
Big Casino Creek Dam	Fergus	80 ft	Satisfactory	Irrigation
Bullhook Lower Diversion	Hill	77 ft	Satisfactory	Flood Risk Reduction
Petrolia	Petroleum	76 ft	Poor	Irrigation
Como Dam	Ravalli	76 ft	Not assessed	Irrigation
East Fork	Hill	76 ft	Satisfactory	Recreation
Black Lake	Missoula	75 ft	Unsatisfactory	Recreation
Browns Dam	Hill	73 ft	Not assessed	Irrigation
Hanson Creek Dam	Fergus	72 ft	Satisfactory	Recreation
Three Mile Reservoir (l.&c.)	Lewis and Clark	70 ft	Poor	Irrigation
Lower Two Medicine	Glacier	70 ft	Satisfactory	Irrigation
Sullivan Dam	Toole	68 ft	Satisfactory	Flood Risk Reduction
Castle Rock Reservoir Dam	Rosebud	67 ft	Satisfactory	Other
Moulton Creek Dam #1	Silver Bow	67 ft	Satisfactory	Water Supply
Tiber Dike	Liberty	65 ft	Not assessed
Cowpath Dam	Toole	65 ft	Satisfactory	Flood Risk Reduction
Bearpaw Lake Dam	Hill	64 ft	Satisfactory	Recreation
Bynum Reservoir Dam	Teton	60 ft	Satisfactory	Irrigation
Deadmans Basin Dam	Wheatland	60 ft	Satisfactory	Irrigation
Delmoe Lake Dam	Jefferson	60 ft	Poor	Irrigation
Tabor South	Lake	60 ft	Poor	Recreation
Flower Creek Dam	Lincoln	59 ft	Satisfactory	Water Supply
Lake Frances East Dam	Pondera	59 ft	Satisfactory	Irrigation
Scott Coulee Dam	Hill	58 ft	Satisfactory	Flood Risk Reduction
Chessman Main Dam	Lewis and Clark	57 ft	Fair	Water Supply
Glacier Lake North Dam	Carbon	57 ft	Satisfactory	Irrigation
Lima	Beaverhead	56 ft	Satisfactory	Irrigation
Ackley Lake Dam	Judith Basin	55 ft	Satisfactory	Irrigation
Georgetown Dam	Deer Lodge	55 ft	Satisfactory	Hydroelectric
Nilan North Dam	Lewis and Clark	54 ft	Satisfactory	Irrigation
Swift Dike (pondera)	Pondera	53 ft	Satisfactory	Irrigation
Powell	Powell	52 ft	Poor	Irrigation
Big Sky Dam	Madison	52 ft	Satisfactory	Recreation
Nilan East Dam	Lewis and Clark	51 ft	Satisfactory	Irrigation
Jocko	Missoula	51 ft	Poor	Irrigation
Doggett Reservoir	Meagher	50 ft	Fair	Irrigation
Broadwater Dam	Broadwater	50 ft	Satisfactory	Hydroelectric
Four Horns	Glacier	50 ft	Satisfactory	Irrigation
Martinsdale, East Dam	Wheatland	49 ft	Poor	Irrigation
Mcdonald	Lake	47 ft	Satisfactory	Irrigation
Green Hollow Creek Dam	Madison	45 ft	Satisfactory	Recreation
Colstrip Diversion Dam	Rosebud	44 ft	Satisfactory	Other
Rainbow	Cascade	44 ft	Satisfactory	Hydroelectric
Lake Creek	Lincoln	44 ft	Satisfactory	Hydroelectric
Taylor, Upper	Powell	43 ft	Satisfactory	Irrigation
Anita Dam	Blaine	42 ft	Fair	Irrigation
Burnt Fork Dam	Ravalli	42 ft	Not assessed	Irrigation
Depression Detention Dam	Carbon	42 ft	Poor	Flood Risk Reduction
Black Eagle	Cascade	41 ft	Poor	Hydroelectric
Ninepipe	Lake	41 ft	Fair	Irrigation
Olson, Oscar (meagher)	Meagher	40 ft	Satisfactory	Irrigation
Upper Dry Fork	Sanders	40 ft	Unsatisfactory	Irrigation
Dry Blood Creek Dam	Petroleum	40 ft	Fair	Flood Risk Reduction
Cottonwood Dam (park)	Park	39 ft	Poor	Irrigation
Madison Dam	Madison	39 ft	Satisfactory	Hydroelectric
Jordan Dam	Park	38 ft	Poor	Irrigation