Lehighton is a borough in Carbon County, Pennsylvania, 86 miles (138 km) north by west of Philadelphia. In the past, it developed early industries because of water power from the Lehigh River. With the location of a repair facility here and its regional operations, the Lehigh Valley Railroad became for years a major employer of thousands of people from the area. Post-World War II railroad and industry restructuring led to job and population losses. From a peak of nearly 7,000 in 1940, the population was 5,537 at the 2000 census. Lehighton is the most populous borough in Carbon County and still the business hub of the county. Lehighton is located in northeast Pennsylvania 26 miles (42 km) north/northwest of Allentown and 35 miles (56 km) south of Wilkes-Barre. Lehighton's elevation varies from 470 feet on Routes 443 and 209 up to 725 feet near the northwest part of town by Mahoning Township border.