The main break probably extended from a point south of Mono Lake to Antelope Valley and from Markleeville northward toward Sierra Valley.

A large part of the crust block to the west of this dislocation also sank down.

This sunken area is now indicated by Lake Tahoe and by its northward continuation, Sierra Valley, separated from each other only by masses of Tertiary lavas....

It is worthy of note that within the area of the range no volcanic eruptions accompanied this subsidence." He continues: "As a consequence of this uplift the erosive power of the streams was rejuvenated, the Cretaceous surface of gentle outline was dissected, and the rivers began to cut back behind the old divide, carrying their heads nearly to the present crest line that separates the slope of the Sierra from the depression of Lake Tahoe." These rivers are the great gold bearing streams that caused the mining excitement of 1849.

They all head near the Tahoe region, and include the Yuba, Feather, American, Mokelumne, Calaveras, Cataract, and Tuolumne.
Here, then, were two crest lines--the old Cretaceous line of which the Crystal Range immediately overlooking Desolation Valley on the west, with Pyramid and Agassiz Peaks as its salient points,--and the new Tertiary crest line, reaching somewhat irregularly from Honey Lake in the north to Mono Lake in the south.