A 1972 recreation plan for the Middle Fork Valley sought to address the inadequacy of the unpaved Minaret Summit entrance road to the monument. "The relatively steep grades, lack of adequate drainage structures, and lack of road surfacing result in more soil loss than is desirable and do not contribute positively toward the quality of the recreational experience." In 1974, Sequoia and Kings Canyon National Parks Acting Superintendent, John Rafferty, put it more directly, noting that "the condition of the access road from Minaret Summit and the pumice dust is the greatest deterrent to monument visitation."
Park managers recognized that while paving the road would reduce the maintenance costs and environmental deterioration, it would likely also increase visitation. The 1976 Monoplan, a Mono-Inyo County Development study, therefore recommended using Inyo National Forest funds to pave the road to Reds Meadow and Devils Postpile contingent upon the initiation of a shuttle bus service to reduce congestion on the road and in parking areas.
The US Forest Service completed paving the road in 1978, and a shuttle bus service from the Mammoth Mountain Ski Area to the Devils Postpile and Reds Meadow was in place the following year, jointly funded by the Forest Service and the National Park Service. It was the first regionally coordinated, mandatory public transport system serving a unit of the national park system. Day users were required to park at the Mammoth Mountain Ski Area and pay $1 per person or $3 per family to use the shuttle; visitors with camping, lodging, or pack trip reservations were allowed to drive into the valley. Buses ran every 15 to 30 minutes from 7 a.m. to 5 p.m. daily from early July through Labor Day weekend.
Visitor reactions were generally positive, but after its budget was cut 3 percent in 1981, the Park Service could not continue to subsidize the shuttle service. The Forest Service therefore requested bids for a contract shuttle and accepted the only offer received, from Quicksilver Stage Lines of Mammoth with the fare set at $5 per person. The public response was harsh, especially regarding the expense for families, and the number of shuttle riders dropped from more than 44,700 in 1980 to just over 18,000 in 1981, which provided minimal profits for the contractor. The number of people entering the valley actually increased, but many day users avoided use of the shuttle by arriving before or after it was in service each day, or by paying $3 for a camping reservation they did not use.
After the initial shock of the 1981 season, however, most visitors became resigned to the shuttle bus. In 1982, when the fare remained the same for individuals but was reduced slightly for families and groups, ridership increased 56 percent and there were far fewer complaints about the cost.
The Mammoth Mountain Ski Area, which replaced Quicksilver as the contract holder in 1986, reported in 1992 that it was losing money at the rate of one dollar for every two collected. By this time, continuing increases in visitation had made the monument dependent on the shuttle service; without it, many visitors would have to be turned away. Eastern Sierra Transit Authority took over management of the shuttle bus in 2012, providing seamless bus service from the town of Mammoth Lakes.
In addition to reducing the dust and parking problems of earlier years, the shuttle service brought a different group of visitors to the monument, including foreign visitors and others less accustomed to roughing it on unpaved roads. The shuttle also helped protect the rustic character of the monument while creating a formal link between it and the rest of the Mammoth Lakes visitor circuit and giving the ski area a direct economic stake in visitation to the monument and the Middle Fork Valley.
For current rules regarding use of the shuttle, see Shuttle Fees and Information.