Mountain Line was founded in 1995, when the City of Morgantown and Monongalia County merged their transit services. Initially, the Mountain Line system served approximately 200,000 passengers per year. Late-night service to the WVU campus began in 2002, growing ridership for the system.
Greyhound discontinued its intercity bus service through Morgantown in 2005, and Mountain Line responded by launching the Grey Line intercity service, which continues to operate as of 2024. Mountaineer Station, a bus station co-located with the WVU Personal Rapid Transit system's Health Sciences Center station, opened in 2007. Monongalia County discontinued much of its funding for transit service in 2016, following a decrease in coal
severance tax receipts. Mountain Line proposed a new property tax levy, which was passed by Monongalia County voters. In recognition of the property tax levy's importance, Mountain Line published schedules that showed the specific services funded by the levy, and added "Levy Funded" graphics to newly purchased buses. The agency faced further challenges in 2018, when local non-emergency medical transportation provider In Touch and Concerned Inc. went out of business. In Touch and Concerned was formerly a partner of Mountain Line, but stopped using space in the agency's facility in Westover after it expanded services. Mountain Line took over some of the company's services with the assistance of local grant funding. During the early days of the
COVID-19 pandemic in West Virginia, Mountain Line expanded its communication through social media, and implemented
social distancing restrictions on its buses. WVU closed the PRT system for over a year beginning in March 2020, instituting its own substitute bus service. Mountain Line service continued, paralleling the PRT and providing additional options to WVU students. Also in 2020, a second property tax levy was passed by Monongalia County voters, providing dedicated funding for Mountain Line services. == Routes ==