Twenty Hill Hollow 
ground, each poised and settled daintily into 
its place at a regular distance from its fellows, 
making a charming fairy-land of hills, with 
small, grassy valleys between, each valley hav- 
ing a tiny stream of its own, which leaps and 
sparkles out into the open hollow, uniting to 
form Hollow Creek. 
Like all others in the immediate neighbor- 
hood, these twenty hills are composed of strati- 
fied lavas mixed with mountain drift in vary- 
ing proportions. Some strata are almost wholly 
made up of volcanic matter — lava and cinders 
— thoroughly ground and mixed by the waters 
that deposited them; others are largely com- 
posed of slate and quartz boulders of all de- 
grees of coarseness, forming conglomerates. A 
few clear, open sections occur, exposing an 
elaborate history of seas, and glaciers, and vol- 
canic floods — chapters of cinders and ashes 
that picture dark days when these bright 
snowy mountains were clouded in smoke and 
rivered and laked with living fire. A fearful 
age, say mortals, when these Sierras flowed 
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