wchamp2 No worries!
After driving around to the east side of the possible bridge location on Forest Road 6S07, I parked where I thought the railroad grade joined the road:
My truck is on the "mainline" and road 6S07 is actually built on a spur track. Here's a rock retaining wall on the edge of 6S07:
Here's another retaining wall on the "mainline":
I was definitely on a railroad grade and followed it for about 500 feet through thick brush and fallen trees. This area was not hit by the Railroad Fire and probably has not seen a fire in over 100 years. Without a fire to clear out the brush most of the MSP grades are nearly impassable. I came out of the brush onto this rock ledge:
Here's a nice view upstream from the rock ledge:
To be continued....