WEST GLACIER, Mont. (AP) — The National Park Service says it is modifying the terms of the prospectus for a concessions contract in Glacier National Park to make it clear the park intends to keep its fleet of 33 red tourist buses on the road.

The Glacier Park Foundation and other groups criticized the prospectus for the 16-year contract, which called for rehabilitating 13 buses and replacing 18 of them with alternative fuel vehicles.

The park service said Wednesday the modified prospectus will make the concessioner responsible for the management and upkeep of the iconic red buses while the National Park Service will rehabilitate them as needed.

Acting Glacier Superintendent Kym Hall says the park appreciates the advocacy for the historic buses by the foundation and others.