We love Trainers Hill Trail! It's a killer, but it's not very long - less than a mile. The hike is much easier after that, if you don't get lost, which we did the first time. Probably did 9 or 10 miles. The secret is knowing that where you are supposed to turn left onto Western States Trail, the trail sign says "Wendell T. Robbie Trail." If you miss that, you end up in the town of Cool and beyond. The good part about getting lost is that we discovered a lot of smaller trails. That gave us great reference the next time we went on the hike. We're going again this weekend and we're going to explore some of the other trails with some confidence. Yes, the signage is poor, and it can get muddy, but if you like a challenge, followed by a nice walk, this is for you. And if you don't get lost, the view of the American River is lovely. I can't wait to do this hike after the wildflowers bloom.
----------FOLLOW UP: we live in Sacramento so we now do this hike several times a year. If you go in the summer, go early, as Trainer Hill has no shade and will kick your butt. And watch out for the critters. Last summer, we were winding our way toward the end. We passed a couple people on horses and as they turned on the switchback, they yelled down to us "two bears are coming your way." Two bears are never good - it was a mother and her teenager. We ran smack into them on the trail. It took a lot of yelling before they finally took off. Black bears in California aren't that big a deal, but mother bears aren't to be taken lightly. Since then, we've talked to others who ran into bears in the same area. Just be prepared to make some noise.