You're right about the big "bump" Russell, it doesn't fit. As you're California Gulch photo shows, there is no way the river could ever be on the right side of the highway. There is only one place where the highway crosses the river twice, back at Salisbury, and the overlay doesn't look like that place. The river in Boulder Gorge area has not changed since the railroad survey was conducted and the overlay should match the Google Earth image pretty closely. While they did alter the stream channel in some places while constructing the grade that place was not one of them. My best guess would be to try and match the overlay to the river.
The other overlay to the Northwest looks to be right on, although the road identified as NF 1145 is actually the old county road that now ends at the dam. Rd. 1145 is the road that crosses the dam, and shows as the road running parallel to the highway in the upper left. The road paralleling the highway between the overlays is the parking area for the ATV trail that crosses the river. (Actually a closed road.) The parking area is constructed on the old grade, and a paved foot trail there is also on the grade. The Boulder Gorge water tank, discussed earlier, was located next to the river more or less between the NF and 1145 on the county road.
I could probably tell more but the overlays obscure some of the details.
Jim