There were once falls at Salmon Falls, now inundated by Folsom Reservoir. The rocks were blasted away in the 1920s, helping with logging operations, which floated timber down the river. Below is a screengrab of our 1873 map of the Georgetown Divide showing the old townsite.
Salmon Falls got its start in 1849 with miners working the creeks, including Sweetwater Creek, which the town grew up next to. Once Folsom Dam was constructed, this entire area flooded. The town’s cemetery was exhumed and the bodies re-buried at the “Re-location Cemetary” at El Dorado Hills.
In low rainfall years, the town re-emerges from its watery fate, and you can visit some of the old town sites. Here is a link to more info on this area.