You can see photographs from the early days of the Casa Grande National Monument and Frank Pinkley in the Mabel Townsley Papers at the Archives and Special Collections.
“The General Land Office took over management of the ruins and hired a young man named Frank Pinkley in 1901 to be the first on-site custodian. In 1903 a shelter roof of corrugated iron supported by redwood timbers was built over the Casa Grande, and between 1906 and 1908 major excavations and repairs of the ruins were conducted under the direction of Jesse Fewkes of the Bureau of Ethnology. Most of the lower walls visible today were uncovered at that time. President Woodrow Wilson proclaimed Casa Grande Ruins to be a National Monument on August 3, 1918 and management of the Ruins was transferred to the National Park Service.” from Casa Grande Ruins National Monument, Arizona, https://www.nps.gov/cagr/learn/historyculture/index.htm (accessed August 12, 2016).
National Park Service turns 100 on August 25th, 2016.