into two ranges.  It is, as it were, ingulfed between two lofty and nearly parallel ridges, one lying to the east and the other to the west.  As the crest of the principal range of the Sierra runs near the western margin of this Lake, this valley is thrown on the eastern slope of this great mountain system.

The boundary line between the States of California and Nevada makes an angle of about 131 degrees in this Lake, near its southern extremity, precisely at the intersection of the 39th parallel of north latitude with the 120th meridian west from Greenwich.  Inasmuch as, north of this angle, this boundary line follows the 120th meridian, which traverses the Lake longitudinally from two to four miles from its eastern shore-line, it follows that more than two-thirds of its area falls within the jurisdiction of California, the remaining third being within the boundary of Nevada.  It is only within a comparatively recent period that the geographical coordinates of this Lake have been accurately determined.

Its greatest dimension deviates but slightly from a medium line.  Its maximum length is about 21.6 miles, and its greatest width is about 12 miles.  In consequence of the irregularity of its outline, it is difficult to estimate its exact area; but it cannot deviate much from 192 to 195 square miles.

    The railroad surveys indicate that the elevation of the
    surface of its waters above the level of the ocean is about
    6247 feet.

Its drainage basin, including in this its own area, is estimated to be about five hundred square miles.  Probably more than a hundred affluents of various capacities, deriving their waters from the amphitheater of snow-clad mountains which rise on all sides from 3000 to 4000 feet above its surface, contribute their quota to supply this Lake.  The largest of these affluents is the Upper Truckee River, which falls into its southern extremity.

The only outlet to the Lake is the Truckee River, which carries the surplus waters from a point on its northwestern shore out through a magnificent mountain gorge, thence northeast, through the arid plains of Nevada, into Pyramid Lake.  This river in its tortuous course runs a distance of over one hundred miles, and for about seventy miles (from Truckee to Wadsworth) the Central Pacific Railroad follows its windings.  According to the railroad surveys, this river makes the following descent: 

Fall
Distance     Fall     per Mile
Lake Tahoe to Truckee       15 Miles     401 Ft.  28.64 Ft
Truckee to Boca              8 "         313 "    39.12 "
Boca to State Line          11 "         395 "    35.91 "
State Line to Verdi          5 "         211 "    42.21 "
Verdi to Reno               11 "         420 "    38.18 "
Reno to Vista                8 "         103 "    12.87 "
Vista to Clark’s            12 "         141 "    11.75 "