Grants Pass is the county seat of Josephine County, Oregon. Located on Interstate 5, northwest of Medford, the city population was 23,003 in 2000 and 30,930 in 2006 making it one of the fastest growing cities in Oregon. Early Hudson's Bay Company hunters and trappers, following the Siskiyou Trail, passed through the site beginning in the 1820s. In the late 1840s, settlers following the Applegate Trail began traveling through the area on their way to the Willamette Valley. The name was selected to honor General U.S. Grant's success at Vicksburg and a post office was established on March 22, 1865.