Rockslide after the Joshua Tree Earthquake, April 22, 1992

Smithwater Canyon, JTNP

The epicenter of this 6.1 magnitude quake was only a couple of miles further into the remote parts of the Park.

Quite a few boulders of this size and even larger came tumbling down that day, off the steep and rocky sides of Smithwater Canyon. At places new boulders completely crossed narrow parts of the canyon, making for boulder scrambling where before was level walking. This photo was taken within a few days of the quake. If you take a look at the boulders strewn across the floor of Smithwater Canyon today, still, you can see where bright patches of inner rock show through the otherwise patenated surfaces, showing where the boulder were scuffed when tumbling down that day, not so long ago. This particular boulder is especially scuffed up from bouncing and plowing its way to its landing spot on the canyon floor.

The much stronger Landers Quake hit just two months later, but the epicenter was 15 miles or so north of the Park, and didn't leave any such rock movements behind that I know of.