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

The Mashel River is a 30-mile-long river located in the southwestern part of Washington State, USA. This river has a rich history, dating back to the early 1900s, when it was a major salmon fishery. Today, the river is mainly used for recreational purposes, including fishing, kayaking, and swimming. The Mashel River is fed by several tributaries, including the North Fork Mashel River and the Little Mashel River. The river flows into Alder Lake, a reservoir created by the Alder Dam, which was constructed in 1945. This dam is used for hydroelectric power generation and flood control. The reservoir also provides water for agricultural and urban use. Additionally, there are several other small dams along the Mashel River, including the Eatonville Dam and the Ohop Creek Dam.