Mill Creek Trail-Ishi Wilderness is a 13.2 mile out and back trail located near Mineral, CA. The trail is rated as moderate and primarily used for hiking.
I hiked this in late March, 2009. It was a little tough to get to...my car wasn't designed for the road to it, with all the large rocks that almost scraped the undercarriage. Once there, you hike beside Mill Creek for most of the time, which is very nice. Most of the surrounding land is pretty dry though. I never saw another person, and I was on the trail for about 5 hours.