Sailor Flat Trail is a 7.9 mile lightly trafficked out and back trail located near Foresthill, California that features a river and is rated as difficult. The trail offers a number of activity options and is accessible year-round. Dogs are also able to use this trail.
Directions from I-80: Take the Foresthill exit and travel 15.5 miles on Foresthill Road to the Foresthill Ranger Station. Continue on the Foresthill Road for 25 miles to Sailor Flat Road and turn left. Go 1 mile north to the trailhead.
This trail is very steep, so be warned ahead of time. That being said, the stamp mill is cool to visit, and the river at the bottom is beautiful. We'll definitely be backpacking through here again!
I went on this as a beginner hike and it was difficult.
Foresthill Road is paved all the way to Sailor Flat Road, and then it turns into rough dirt. If you are in a car would will likely need to park just off Foresthill and go from there. The turnoff can be hard to recognize without a GPS because it's road sign is knocked over in a ditch. Starting the trail from Foresthill Road it is 4.3 miles and 3060 vertical feet to the river - most of it on a very rough, steep 4WD road with a number of large fallen trees across it. I'd say bring a chainsaw if you plan to drive it (as of 4/2015). Once at the "intersection" we found a shot-up notice board next to a shot-up trail sign that was on the ground, we made a left and walked down the even rougher 4WD road to Oak Flat where the trail technically begins, and where we found even more bullet-ridden signs (seriously guys).
The actual trail is in good shape, if also extremely steep. The whole first switchback is a nice exposure of Early Jurassic marine slate/shale where you can find lots of ammonite casts - mostly fragmentary, they look like spiral seashells about an inch across. They seem especially common around the first turn with the 'no motorcycles' sign, eroding out of the hillside there.
Don't take the fossils, as a) it's illegal, b) they aren't worth anything, and c) they would eventually end up in the trash.
Further down you will probably stumble upon the Trinidad Mine, the upper building is totally wrecked but if you go downhill you will find the large, two-story stamp mill building. And finally if you want to brave the 40-degree (hands-and-knees) incline down to Sailor Canyon creek you will find endless waterfalls and pools.
The river at the end of this trail is much like Mumford - mixed gravel and pools and shaded with trees. There is a nice campsite just around the corner in Sailor Canyon. As with Mumford it doesn't look like many people continue on the American River Trail here. We followed it two miles downriver to a campsite just upstream of Big Granite Creek across the river. The trail somehow goes up and over a huge rocky ridge there but we weren't able to find it. Between Sailor and this point the trail is followable but pretty overgrown and required endless climbing over large fallen trees, especially in the burned area around New York Canyon.
The trail is absolutely brutal if you do it from Foresthill Road but still easily worth it, just make it at least an overnight.
Very difficult switchbacks down and back up. Elevation change of 2800ft. I've been going since I was 15. Definitely a 1-4 night overnight trip to enjoy the river and recover from blisters. There are beautiful waterfalls once you're hiking along the river, great jumping rocks, great places to set up camp.
My son and I did this trip for a liitle fly fishing. We started at "sailor flat bar" trail head, so we drove the first mile and a half (extremly rough 4wd road).It's straight down, and my kness started hurting before we got to the bottom. We fished for an hour then back on the trail. Straight up (over a 1000 ft gain in 2 miles) for 2 and a half hours. WOW! When we git back to the truck we found that a bear had attacked our truck. What a trip!