About
Cannonball River, North Dakota — 1804 Lewis Clark Pass, 1840s-1880s Frontier Ranching, 1990s-2010s Standing Rock 135-mi. Hunkpapa Lakota territory for generations before European contact, the Cannonball flows 140 miles through Slope and Sioux counties from prairie headwaters to the Missouri River confluence at Standing Rock. The upper 50 miles through Slope County to Hettinger run as a narrow prairie stream averaging 160 CFS, while the lower 90 miles widen through Standing Rock Sioux Reservation lands. Class I water throughout, with optimal flows between 50–500 CFS on USGS gauge 06354000. Standing Rock Tourism coordinates river access through reservation corridors. The Cannonball gained national attention in 2016 during the Dakota Access Pipeline protests, when water protectors camped along its banks to defend the river and the Missouri confluence from potential contamination.
River conditions are community-verified. CFS ranges, difficulty ratings, and access points may not reflect every flow level or seasonal change. Always check current conditions, scout unfamiliar rapids, and paddle within your skill level.