This is the former Salmon Falls Bridge, on Folsom Lake. Usually, it's under water, but our winter has been exceptionally dry, and the expected water from the snowpack is non-existent so far.
This bridge used to span the low water crossing of the south fork of the American River. In the late 1950's, Folsom Dam was built, forming Folsom Lake, and combining the north and south forks of the American River. I was able to paddle under and then walk on this bridge yesterday - it's in surprisingly good condition!