Total streamflow across the Ruby River was last observed at 119 cfs, and is expected to yield approximately 236 acre-ft of water today; about 111% of normal. Average streamflow for this time of year is 107 cfs, with recent peaks last observed on 2011-07-01 when daily discharge volume was observed at 3,719 cfs.

Maximum discharge along the river is currently at the Ruby River Near Twin Bridges Mt reporting a streamflow rate of 188 cfs. However, the streamgauge with the highest stage along the river is the Ruby River Ab Reservoir Nr Alder Mt with a gauge stage of 3.03 ft. This river is monitored from 3 different streamgauging stations along the Ruby River, the highest being situated at an altitude of 5,410 ft, the Ruby River Ab Reservoir Nr Alder Mt.

The Ruby River is a tributary of the Jefferson River, which eventually flows into the Missouri River. It is around 76 miles long and is located in southwestern Montana. The river was named after the garnets found in the area, which are a deep red color, like the precious stone. The river has a substantial flow and is used for irrigation of crops and pastures, as well as for recreational activities such as fishing, rafting, and kayaking. There are several reservoirs and dams along the river, including Ruby Reservoir, which was built in the 1930s to provide irrigation water for local farmers. The river has a rich history, as it was once home to Native American tribes and was an important site for fur trading in the 1800s.