I didn’t find the hike to be very strenuous (relatively speaking). Not that I wasn’t breathing hard, but I believe this is the longer, but more gentle/ gradual way to get to San G.
What type of vehicle do you have? Last time I was there, someone drove up in a Honda Accord sedan… I think there were 4 people so it was probably weighted down a bit.
Honestly, there are only a few spots where you have to be extra careful. Most of the road is a smooth(ish) or moderately bumpy dirt road. I watched out, mostly, for sharp rocks.
It’s 7 miles back to the trailhead. Going slow (10 mph?), it will take you 45 minutes or so. I don’t go slow anymore. 🙂
Sorry, I don’t know anything about Momyer.