The San Pablo Creek Watershed is a large and geographically diverse stream located East of the San Francisco Bay. San Pablo Creek historically provided habitat for an abundant population of steelhead trout, a federally listed threatened species. However, in 1919, the East Bay Municipal Utility District (EBMUD) constructed a dam and reservoir on San Pablo Creek. Since the 1950’s, residents and regulators have observed a decline in the abundance of anadromous fish. Our study assesses San Pablo Creek’s current viability for anadromous fish, by examining the input of water from perennial tributaries of San Pablo Creek and the mainstem’s habitat characteristics. By analyzing flow patterns and features including pool-riffle sequences and embeddedness, we determined that San Pablo Creek provides adequate rearing habitat for steelhead trout, but limited spawning habitat.