Total streamflow across the Boulder River was last observed at 230 cfs, and is expected to yield approximately 456 acre-ft of water today; about 80% of normal. Average streamflow for this time of year is 287 cfs, with recent peaks last observed on 2011-07-01 when daily discharge volume was observed at 9,175 cfs.

Maximum discharge along the river is currently at the Boulder River At Big Timber Mt reporting a streamflow rate of 136 cfs. However, the streamgauge with the highest stage along the river is the Boulder River Near Boulder Mt with a gauge stage of 5.03 ft. This river is monitored from 2 different streamgauging stations along the Boulder River, the highest being situated at an altitude of 4,823 ft, the Boulder River Near Boulder Mt.

The Boulder River is located in southwestern Montana and is approximately 66 miles long. The river has a rich history, with evidence of human use dating back over 10,000 years. In the late 1800s, gold was discovered in the area, which led to increased settlement and development. Hydrologically, the Boulder River is fed by snowmelt and precipitation in the surrounding mountains, providing important water resources for agricultural purposes. The river also features several reservoirs and dams, including the Boulder River Dam, which was built in 1908 and is still in operation today. Recreationally, the Boulder River is popular for fishing, camping, and hiking, with many scenic trails and camping areas located along its banks.