Hike literally on black obsidian to the edge of an ancient caldera
This is a short (3 miles out and back) steep (2,000 feet) hike on a mountain with large obsidian fields. A fun thing to do here is to sandbag your kids. Let them know you “may” find some black glass obsidian and for them to keep watch. Within a few hundred yards you are literally walking on obsidian.
The start of the hike is not well marked at all and the two times we’ve visited it almost seems like the forest service is trying to hide the start of the trail. But it is a trail, though it gets steep and loose for a short section near the top. I’m not at all sure why it isn’t more popular. We love it.
To get there turn off Highway 120 and turn onto the unpaved but well graded and signed Black Canyon Road. If coming from Lee Vining the turnoff is 32 miles east of Highway 395. After 0.8 miles turn right at an intersection onto Sawmill Meadows Road and continue 6.6 miles to another intersection and turn left to stay on Sawmill Meadows Road. After 3.2 miles keep right and continue another 0.4 miles to the trailhead. There is no sign, so you might want to use the GPS coordinates to ensure your arrival: (37.77388° N, 118.68380° W). Trail is on the right and heads uphill.
I called the forest service to ask about collecting obsidian. After they questioned me about whether I was going to fill a truck with obsidian (no) or sell it (no), they did say that collecting small quantities for personal use is OK. They did reiterate that there is NO collecting in the Mono Scenic area which this isn’t in.