Nevada Revised Statutes Title 20. Counties and Townships: Formation, Government and Officers § 243.345. Lake County created--1861

There shall be a county, to be known as Lake County, to include all that part of the Territory of Nevada within the boundaries described as follows: Beginning at the northwest corner of Washoe County, and running easterly along the northern boundary of Washoe County to the mouth of the Truckee River; thence due east to the summit of the first range of mountains east of the Truckee River; thence in a northerly direction, along the range, and the main granite range of mountains, to the Oregon line; thence west, along the line, to the summit of the Sierra; thence south, along the summit, to the place of beginning.