IRRIGATION 97 



Agricultural and Climatic Conditions. 



Area for which the service is prepared to supply water, season 1913, 12,800 acres. 



Area under rental contracts, season of 1913: 1,170 acres. 



Length of irrigating season: From March 1 to September 15, 199 days. 



Average elevation of St. Mary Storage: 4,500 feet above sea level. 



Average elevation of irrigable area: 2,200 feet above sea level. 



Average annual rainfall on St. Mary Storage: About 24 inches. Rainfall at 

 Babb, Montana, 1912, 22.7 inches. 



Average annual rainfall on irrigable area: For 30 years at Havre, 13.58 inches 

 (for 1912 at Havre, 12.26 inches); for 7 years at Malta, 13. 7G inches; for 1912 at 

 Malta, 17.56 inches. 



Range of temperature on irrigable area: -50 to 103 degrees F. 



Character of soil of irrigable area: Sandy loam and gumbo. 



Principal products: Alfalfa, hay, grain and vegetables. 



Principal markets: Minneapolis and St. Paul, Minn. Local. 



SUN RIVER PROJECT. 

 Location. 

 Counties: Teton, Lewis and Clark and Chouteau. 

 Townships: 20 to 25 North, Rs. 3 E. to 8 W., Montana Meridian. 

 Railroads: Great Northern; Chicago, Milwaukee & St. Paul. 



Railroad stations: Vaughn, Power, Button, Collins, Largent, Fort Shaw, Simms, 

 Riebling, Gilman and Choteau, Montana. 



Water Supply. 



Source of water supply: Sun River and tributaries Deep Creek, Bowl Creek 

 and Basin Creek. 



Area of drainage basin: Sun River, 1,070 square miles; Deep Creek, 260 square 

 miles; Bowl Creek, 9 square miles; Basin Creek, 15 square miles. 



Annual run-off in acre-feet: 1905-1912, North Fork of Sun River, near Augusta; 

 maximum, 805,000; minimum, 378,000; mean, 640,000. Willow Creek, near Augusta, 

 1906-1912; maximum, 35,300; minimum, 7,900; mean, 21,000. Sun River at Sun River, 

 1906-1911; maximum, 1,140,000; minimum 390,000; mean, 816,000. South Fork of Run 

 River, near Augusta, 1905-1912; maximum, 147,000; minimum, 28,000; mean, 75,000. 



Data for Complete Project. 



Reservoirs: Willow Creek — Area, 2,696 acres; capacity, 86,000 acre-feet; length 

 of spillway, 200 feet; elevation of spillway, 100 feet above stream bed. Sun River 

 Storage— Area, 3,540 acres; capacity, 269,000 acre-feet; length of spillway, 580 feet; 

 elevation of spillway above stream bed, 321 feet. Pishkun — Area, 1,542 acres; 

 capacity, 45,700 acre-feet. Mudd Creek — Area, 1,828 acres; capacity, 33,000 acre-feet. 

 Benton Lake — Area, 9,300 acres; capacity, 144,000 acre-feet. 



Storage dam: Willow Creek — Type, earth fill; maximum height, 110 feet; length 

 of crest, 1,045 feet; volume, 452,000 cubic yards. Sun River Storage — Type, masonry; 

 maximum height, 329 feet; length of crest, 989 feet; volume, 296,500 cubic yards. 

 Jishkun — Type, earth fill; maximum height, 48 feet; length of crest, 3,500 feet; 

 volume, 440,000 cubic yards. Benton Lake — Type, earth fill; maximum height, 35 feet; 

 length of crest, 120 feet; volume, 12,000 cubic yards. 



Diversion dams: Sun River — Type, concrete masonry; maximum height, 140 

 feet; length of crest, 190 feet; volume, 3,300 cubic yards. Deep Creek — Type, re- 

 enforced concrete weir; maximum height, 12 feet; length of crest, 100 feet; volume, 

 500 cubic yards. 



Length of canals: Fort Shaw Unit — 18 miles, with capacity of from 50 to 300 

 second-feet. Project as far as surveyed, 240 miles, with capacities greater than 300 

 second-feet; 110 miles, with capacities from 50 to 300 second-feet; 140 miles, with 

 capacities less than 50 second-feet; balance of canals not located. 



Tunnels: Number, 5; aggregate, length, 4,980 feet. 



Dikes: Number, 5; aggregate length, 22,000 feet. 



Irrigable area entire project, 216,346 acres; Fort Shaw Unit. 16,346 acres. 



Present status of irrigable lands: 110,477 acres entered subject to the Reclama- 

 tion Act; 2,405 acres open to entry; 54,108 acres withdrawn from entry; 14.680 acres 

 state land; 34,676 acres in private ownership. 



Results to June 30, 1913. 



Canal structures: Costing over $2,000 each — Concrete, 6. Costing from $500 to 

 $2,000 each— Concrete, 6. Costing from $100 to $500 each— Concrete, 38; wood, 16. 

 Costing less than $100 each — Concrete, 135; wood, 473. 



Bridges: Steel — 8, less than 50 feet in length; total length, 225 feet. Combina- 



— The more Montana ground is cultivated, the better the crop. 



