claim, federal land agent Samuel J. Holsinger detailed the physical setting of the canyon and the sites, noted prehistoric road segments and stairways above Chetro Ketl, and documented prehistoric dams and irrigation systems. His report went unpublished and unheeded. It urged the creation of a national park to safeguard Chacoan sites. The next year, Edgar Lee Hewett, president of New Mexico Normal University (later renamed New Mexico Highlands University), mapped many Chacoan sites. Hewett and others helped enact the Federal Antiquities Act of 1906, the first U.S. law to protect relics; it was, in effect, a direct consequence of Wetherill's controversial activities at Chaco. The Act also authorized the President to establish national monuments: on March 11, 1907, Theodore Roosevelt proclaimed Chaco Canyon National Monument. Wetherill relinquished his land claims. In 1920, the National Geographic Society began an archaeological examination of Chaco Canyon and appointed Neil Judd, then 32, to head the project. After a reconnaissance trip that year, Judd proposed to excavate Pueblo Bonito, the largest ruin at Chaco. Beginning in 1921, Judd spent seven field seasons at Chaco. Living and working conditions were spartan at best. In his memoirs, Judd noted dryly that "Chaco Canyon has its limitations as a summer resort". By 1925, Judd's excavators had removed 100,000 short tons of overburden, using a team of "35 or more Indians, ten white men, and eight or nine horses". Judd's team found only 69 hearths in the ruin, a puzzling discovery as winters are cold at Chaco. Judd sent A. E. Douglass more than 90 specimens for tree-ring dating, then in its infancy. At that time, Douglass had only a "floating" chronology. it was not until 1929 that a Judd-led team found the "missing link". Most of the beams used at Chaco were cut between 1033 and 1092, the height of construction there. In 1949, the University of New Mexico deeded over adjoining lands to form an expanded Chaco Canyon National Monument. In return, the university maintained scientific research rights to the area. By 1959, the National Park Service had constructed a park visitor center, staff housing, and campgrounds. As a historic property of the National Park Service, the National Monument was listed on the National Register of Historic Places on October 15, 1966. In 1971, researchers Robert Lister and James Judge established the "Chaco Center", a division for cultural research that functioned as a joint project between