Six hundred years ago, a massive explosion heated rock and ground water, causing a large blast zone. Three craters were formed. Today, snow melt and rainwater create emerald green pools in the craters. Accessibility: 1.4 miles (2.25 km) round-trip uphill hiking trail. Directions: From the Mammoth Scenic Loop follow signs to Inyo Craters. Take 1.3 mile (2km) unpaved road to trailhead.