Inyo Craters

EFFORT Minimal
LENGTH0.7 miles
GEOLOGICAL FEATURE(S)Volcanism
LOCATIONInyo National Forest
CONTACT 760-934-2289
TRAILHEAD COORDINATES
OFFICIAL WEB SITEhttp://vulcan.wr.usgs.gov/Volcanoes/LongValley/framework.html

If you don't have a GPS unit, or you just want to know where you're going before you get there, use the alternate Driving Directions to the trailhead.


(Photo courtesy of the USGS)

Access is free. There are no facilities.

Description: This short trail leads to three fascinating, young volcanic craters, two with lakes in them. The Inyo Craters are one of the most recently active eruptive centers of the Long Valley Caldera, dating from about 500 to 600 years ago. There are three main craters--North, South, and the crater at the summit of Deer Mountain. There are several associated smaller craters and domes in the chain that runs along a north-striking fault system and extends northward to the Mono Craters.

The Inyo Craters were created by hydrothermal explosions when the magma rising underground met groundwater, creating a steam explosion that blew off the overlying crust and threw debris outward. This was not a lava eruption. From the parking area at 8,000 feet, head out on a trail shaded by pine trees. You will climb about 300 feet along the way to the rim. The trail passes between two picnic tables just as you emerge from the forest, approaching a slight rise towards the edge of a huge pit in the ground. When you reach the south crater rim after a mere quarter mile, use the viewing platform to look inside the 600-foot wide hole, over 200 feet deep. The steep sides are only sparsely vegetated, so this crater is much easier to view than the north crater. At the bottom is a murky-looking turquoise lake.

Walk right along the rim to a second viewing area. This area was closed when we visited because the edge of the crater had eroded back to start gobbling up the railingís feet. As a matter of fact, one plastic warning sign lay far below inside the crater. Either it fell in or some rude person threw it. Either way, let this be a caution to keep back from the lip of the crater.

Continuing around to the north side of the south crater, you will notice, suddenly, that there is another crater on your right. You are standing on the narrow rim between the two. Turn back and walk east and then north along the rim of the north crater. It is forested and inhabited by many birds and small animals. You canít see the craterís features as well, but you can see how large it is. It too is about 600 feet in diameter, and is somewhat shallower than the south crater at 150 feet deep. The trail heads up steeply for about 400 yards to the north towards the top of Deer Mountain and the Summit Crater. It has no lake in it. We will leave it up to you to decide if it is worth the struggle. There are good views from up there, and we know how the high points beckon.

Return by the same route.

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Driving Directions: From Mammoth Lakes on Highway 203 (Main Street), turn right where it becomes Lake Mary Road and proceed to Mammoth Scenic Loop (Forest Service Road 3S23). Turn right onto it and drive to a dirt road signed for Inyo Craters on the left. Follow this dirt road and the signs for 1.5 miles to the trailhead. The road is passable for all vehicles in good weather.