[6] The Dudidontu River's watershed covers 964 km2 (372 sq mi),[5] and its mean annual discharge is 15.4 m3/s (540 cu ft/s).

[8] From its source the river flows west in a U-shaped valley of Level Mountain,[8][9] then south, then by Ketchum Lake,[10] where the Dudidontu turns and flows generally north for the rest of its length, about 112 km (70 mi) in total.

[4] It flows by Camp Island Lake and between Level Mountain and the Heart Peaks.

[12][13] The middle Dudidontu River, from Camp Island Lake to 6.4 km (4.0 mi) below Kakuchuya Creek, meanders through a wide floodplain, providing excellent spawning habitat for Chinook salmon.

Below this section the lower Dudidontu flows through a 19.2 km (11.9 mi) long canyon with steep slopes of mud, boulders, and shale, with no vegetation.