Maximum discharge along the river is currently at the reporting a streamflow rate of cfs. This is also the highest stage along the Greys River, with a gauge stage of ft at this location. This river is monitored from 1 different streamgauging stations along the Greys River, the highest being situated at an altitude of ft, the .

The Greys River is a 62-mile-long tributary of the Snake River, located in western Wyoming. Historically, the area was used by various Native American tribes, and later by fur trappers, miners, and ranchers. The river's hydrology is fed by snowmelt and precipitation, and it flows through the Bridger-Teton National Forest. The most significant reservoir on the river is the Little Greys River Dam, which was completed in 1986 and provides water for irrigation and recreation. The river is a popular destination for fishing, hiking, and camping, and the surrounding area is used for cattle grazing and farming. In recent years, concerns have been raised about the impact of recreational activities on the river's ecosystem, particularly regarding the use of off-road vehicles.