With the Park Service came improved roads and trails, administrative sites, campgrounds, sanitation, and much-needed utilities. By 1919, the Santa Fe Railway was hauling 60,000–100,000 gallons of water daily to the South Rim from Flagstaff via rail car. The septic system installed with the construction of El Tovar, unable to meet increasing demand, had overflowed into an open ditch along the railroad tracks. Employees were housed in a ramshackle collection of boxcars, tents, and shanties literally on the other side of the tracks.

The less visited North Rim was virtually ignored. One or two rangers assigned to that area of the park fended for themselves, often staying in vacated Forest Service cabins or bunking with game manager Jimmy Owens.

In order to fund infrastructure, the fledgling Park Service clearly needed the large capital investment provided by the Santa Fe Railway and Fred Harvey Company on the South Rim, and the Union Pacific Railroad and Utah Parks Company on the North Rim. Only a few family businesses were awarded concessioner contracts, among them the McKee family on the North Rim, and the Babbitts, Verkamps, and Kolbs on the South Rim. Some, like the Bass family, were bought out. Ralph Cameron’s reign ended not long after his unsuccessful bid for the senate in 1926. In 1928, Cameron’s holdings transferred to the Park Service.

By 1929, with capital provided by concessioners, the park developed housing, utilities, and basic services to meet the needs of employees and visitors, who numbered 184,000 that year. The park weathered the Great Depression, relying on Civilian Conservation Corps (CCC) labor for needed improvements. But World War II brought a loss in funding, drops in visitation, and a scarcity of materials. Nearly half the park’s staff left for war-related jobs, and many lodges and attractions closed. During the last year of the war, only 74,000 people visited the park.

Yet it wasn’t the bust but the boom that threatened the park most. The year after war’s end, 334,000 people visited the park, and the steadily rising number of visitors outstripped the Park Service’s ability to manage. Vandalism, littering, theft, traffic accidents, and frequent rescues burdened ranger services. Adding to the burden was a bed shortage: By 1949, 15 to 30 percent of visitors seeking overnight lodging had to be turned away.

In 1956, the Park Service’s hopes for government funding materialized with Mission 66, a 10-year program intended to add infrastructure to national parks. Efforts focused on the South Rim, and many park additions, including the Yavapai, Kachina, and Thunderbird Lodges, date to this program, which extended into the early 1980s at Grand Canyon.

In 1965, the Union Pacific Railroad donated the North Rim’s water system, and the Park Service launched plans to pipe water from Roaring Springs to the South Rim. Seven footbridges and the cross-river Silver Bridge carried more than 12 miles of pipeline to Indian Garden. Just before its completion, the pipeline was virtually destroyed by a record-breaking flood that swept down Bright Angel Canyon. The transcanyon pipeline was finally completed in 1970. With improvements, the pipeline continues to serve the South Rim today, though there is growing concern about its adequacy and the burden on groundwater in the canyon region.