Lost Horse Mine is one the best-preserved gold mines found in Joshua Tree National Park and is one of the park's highlights. The mine can be accessed either by hiking the full 6.7 loop, or by a 4 mile out-and-back hike. The loop hike wraps around Lost Horse Mountain and provides spectacular views into Pleasant Valley. The out-and-back follows an easy trail and provides direct access for those only wanting to see the mine.
We recommend hiking the loop counter-clockwise, which gets the monotonous wash slog done first and saves the mine for the later half of the hike. The trailhead can be a little tricky to find. Instead of heading up the marked trailhead located at the end of the parking lot, look towards the south entrance to the parking lot. The trail starts on the opposite side of the hill to the south and crisscrosses over a large wash. This stretch of trail can be challenging to follow because it is thin and often crosses the wash (1). Look for signposts every 1/4 mile to verify that you are still on track.
After 2.25 miles the trail starts to climb up the southern side of Lost Horse Mountain. The trail then winds its way around the flank of the mountain, passing an old chimney (2) -- remnants from the Optimist Mine Bunkhouse -- and then steeply climbs 400 feet providing stunning views into Pleasant Valley (3). Malapai Hill and Geology Tour Road are visible near the top of Lost Horse Mountain. If you wish to gain the summit, scramble off-trail a short distance once you reach the saddle 4.5 miles from the trailhead. From the saddle you can look down unto Lost Horse Mine.
Drop down the short hill and then immediately gain the elevation back to reach the mine itself (4). Take some time to explore the remains of this historic site. Between 1894 and 1931 the mine produced over 10,000 ounces of gold and 16,000 ounces of silver (roughly worth $5 million today) (5). Interpretive signs provide more information about the site's rugged history.
The route back is the out-and-back option those who wanted a shorter trek would take. From the mine, it's a 2 mile gradual downhill hike on a well-established trail (6). Bet you're glad you did the other part of the loop already!