Together with its major tributary, the Puerco River, it drains an area of about 26,500 square miles (69,000 km2) in eastern Arizona and western New Mexico.

The river then turns north, meandering through Richville Valley, before emptying into Lyman Lake, impounded by an irrigation dam built in 1912.

[5] The Little Colorado passes Joseph City and crosses the Southern Transcon route of the BNSF Railway (originally the Atchison, Topeka and Santa Fe Railroad), now winding north into Coconino County.

Emerging into the desert again, the Little Colorado skirts the eastern edge of Wupatki National Monument and passes the town of Cameron, where it is bridged by U.S. Highway 89.

The depth of the canyon is such that groundwater is forced to the surface, forming numerous springs that restore a perennial river flow.

[7] Runoff typically peaks twice a year, first in the early spring (February–April) from snow melt and highland rain; and in the summer (July–September) from monsoon storms.

The annual runoff is extremely variable with the possibility of no flow occurring due to a weak snow pack or lack of summer rain.

Only the upper reaches of the river above St. Johns, and the lowermost stretch below Cameron, flow year round; the middle section is basically a huge arroyo that carries water only during the wet seasons.

[9] Human activity in the Little Colorado River watershed dates back to the early Holocene epoch, in the last glacial period.

Nomadic hunter-gatherers inhabited the relatively water-rich and diverse upper basin of the Little Colorado for almost 8,000 years before the Navajo, Apache and Hopi tribes populated the area.

It is only 30 to 50 [yards] wide now and in many places a man can cross it on the rocks without going on to his knees ... [The Little Colorado was] as disgusting a stream as there is on the continent ... half of its volume and 2/3 of its weight is mud and silt.

The river is normally a bright blue color caused by dissolved travertine and limestone in the water, similar to Havasu Creek, another major tributary of the Colorado within the Grand Canyon.

[14] In the 1870s, Mormon colonists migrated southwards from Salt Lake City and settled in the lower part of the Little Colorado River valley.

[19][20] Later, Hispanics began to move into the Little Colorado River watershed from the Rio Grande area, establishing St. Johns and Concho.

[21] For many years, Mormons were the primary group living in the watershed until the 1960s, when their independent towns and farms were absorbed into the growing Arizonan economy.