The eastern boundary of Nevada Territory had been defined as the 39th meridian west from Washington, but when gold discoveries were made to the east the Nevada territorial delegation to Congress requested the boundary be moved east to the 38th meridian, which Congress granted in 1862.

Congress granted the request in 1867, giving Nevada all of the western end of Arizona Territory.

[5] The exact location of the due north-south California–Nevada border, between Lake Tahoe and the intersection with the southern boundary of Oregon at the 42nd parallel, was contentious and was surveyed and re-surveyed well into the 20th century.

[6] Congress transferred some of the lands west of the Colorado River including Pah-Ute County, Arizona Territory to the State of Nevada on May 5, 1866.

Part of this southern tip of Nevada was established as Clark County in 1909 and contains the city of Las Vegas.