There are 10 US Post Offices in Inyo County serving a total of 21,267 residents equating to 2,127 residents per post office. It's estimated that approximately 33,945 packages are handled across the 10 county post offices annually. Inyo County is a county located in the U.S. state of California. As of the 2010 census, the population was 18,546. The county seat is Independence. Inyo County is located on the east side of the Sierra Nevada and southeast of Yosemite National Park in Central California. It contains the Owens River Valley; it is flanked to the west by the Sierra Mountains and to the east by the White Mountains and the Inyo Mountains. Mount Whitney, the highest peak in the Contiguous United States, is on Inyo County's western border (with Tulare County). The Badwater Basin in Death Valley National Park, the lowest place in North America, is in eastern Inyo County. The two points are not visible from each other, but both can be observed from the Panamint Range on the west side of Death Valley, above the Panamint Valley. It has the biggest elevation difference of all of the counties and county-equivalents in the contiguous U.S.A."