Once the dust had settled from the successful congressional battle and the park's creation was a certainty, the Park Service established a local administration and began to run its newest acquisition. The new park covered more than 454,000 acres of territory, the vast majority being above tree line, and included the fifty-year-old General Grant area. The act also authorized the president, by proclamation, to add lands within Redwood Mountain to the park, an action FDR soon took. In subsequent meetings Sierra and Sequoia national forest supervisors reported that the new park contained approximately 350 miles of trails, including access trails from both the east and west slopes and the John Muir Trail from the north. In addition, the Park Service inherited a few fire lookout stations near the two excluded canyons, a couple of inconsequential mineral exclusions, and nine lifetime grazing permittees. The grazing permits, resulting from the compromise negotiations, were located chiefly in the Roaring River and Sugarloaf Creek areas. Secretary Ickes and NPS Director Cammerer initially appointed Guy Hopping, superintendent of tiny General Grant National Park, as acting head of the huge new unit. But when Colonel White returned to Sequoia, his long-time associate and friend Eivind Scoyen took over at Kings Canyon. The administration of Sequoia National Park meanwhile loaned several personnel and some equipment to assist in early operations, particularly at what was now called the Grant Grove area, a well-established visitor destination. A few months later, on June 9, Sequoia personnel again assisted as the Redwood Mountain Grove was officially dedicated. [36]

It is understandable that the Kings Canyon staff would rely on its fifty-year-old neighbor park and it illustrated the close relationship the two staffs maintained during the new unit's short tenure as a separate administration. In 1943 in the midst of World War II the government suspended independent administration of Kings Canyon. After only three years, the new park united with Sequoia under Colonel White, and the two parks continue today as a single administrative unit.

Amid the flush of victory and excitement over the new wilderness park, though, problems had to be addressed. Ironically, these problems did not come with the 450,000 acres of wilderness in the high Sierra. They did not come with the great grove of giant sequoias so near to Generals Highway in Redwood Mountain. They did not even come with the heavily developed, fifty-year-old property at Grant Grove. Rather, they came with a 2,879-acre piece of land the National Park Service did not even officially control, and therein lay part of those problems. For the next twenty-five years the canyon of the South Fork was to bedevil the Park Service. It was a spectacular area, accessible to tourists, controlled by the Forest Service, but an area the Park Service had solemnly vowed to develop and maintain. On top of all that, it still lay under the heavy threat of potential inundation by reservoir waters. Who would administer the canyon's development? How large would that development be and where in the valley would it be located? These were the questions of Kings Canyon National Park.