borough (town), seat of Carbon county, eastern Pennsylvania, U.S., on the Lehigh River, in a valley of the Pocono Mountains, 22 miles (35 km) northwest of Allentown. It was created in 1954 with the merger of the boroughs of Mauch Chunk (“Bear Mountain;” inc. 1850) and East Mauch Chunk (inc. 1854) and was named for Jim Thorpe (Thorpe, Jim) (1888–1953), the famous Native American athlete. Thorpe's remains were brought from Oklahoma and interred in a nearby mausoleum (the Jim Thorpe Memorial).

Following the local discovery of anthracite coal in 1791, the Lehigh Coal and Navigation Company laid out the site and there built the first industrial railroad in the United States (1828), a gravity switchback line that hauled coal to the Lehigh Canal. Asa Packer, a coal baron, founded the Lehigh Valley Railroad (Lehigh Valley Railroad Company) to replace the canal in 1855. Mining has given way to tourism as the borough's economic mainstay. Flagstaff Mountain Park and Glen Onoko Falls are nearby scenic spots. Pop. (1990) 5,048; (2000) 4,804.