At Apollinaris Spring (10 miles from Mammoth Hot Springs, altitude 7,300 feet) is a landing platform on the left of the road for those tourists who wish to stop and try this water. On the opposite side of the road is a good camping place, the next camp site being 4 miles farther on the right side of the road.
Obsidian Cliff (12 miles from Mammoth Hot Springs, altitude 7,350 feet) is a cliff of hard, black volcanic glass. It is the most prominent exposure of this rock in the Park. Obsidian also occurs in the red and white forms. It was much used by Indians for arrow heads and other stone implements, this being one of the few points in the Park frequented by them before its discovery by white men. On the right at this point is Beaver Lake, the dam here being very long and heavy. An old beaver house can be seen near the south end of the lake.
A camp site (14 miles from Mammoth Hot Springs) is passed a mile and a half south of Beaver Lake; next camp site is just south of Bijah Spring, 3 miles farther on.
Roaring Mountain (15½ miles from Mam-
