Spring and autumn are relatively dry seasons when the skies may remain cloudless for weeks at a time. In September a great range of temperature from night to day—as much as 45°—is noticeable. [Illustration: Porcupine.] The winters are mild. The temperature rarely drops to zero or below, and there are very few prolonged periods of cold weather. Infrequent snows are usually light, and melt quickly. Many days are warm and cloudless. At the time that the Aztec pueblo was inhabited, no doubt a few deer, pronghorn (“antelope”), and bighorn could be found in and near the valley. Occasionally, deer still may be seen along the river to the north of Aztec Ruins. Many of the smaller animals which were familiar to the people of the Aztec pueblo are still present in the valley and may occasionally be observed in the monument. Jackrabbits, cottontails, rock squirrels, skunks, porcupines, and an occasional gray fox, all of which were probably well known to the Pueblo people, frequent the monument. Gambel’s quail and pheasants, which are both relative newcomers, may also be seen in the monument. Ducks, geese, and a few large shore birds may be seen along the river during the cooler months. Meadowlarks, robins, and numerous other birds may be seen during warmer months. [Illustration: Bobcat.] Several species of lizards and a few bullsnakes (which are harmless and beneficial and should not be disturbed) may be observed around the ruins area during summer. _Establishment and Administration_ Aztec Ruins National Monument was established by Presidential proclamation on January 24, 1923. Most of the land was donated to the Government by the American Museum of Natural History in 1921, 1928, and 1930. In 1931 an additional 6.8 acres was purchased by the Federal Government from the heirs of H. D. Abrams who had originally owned the entire site. And in 1947, the Southwestern Monuments Association purchased the 1.2 acres containing the Hubbard Mound and presented it to the Government. The monument, now containing 27.1 acres, is administered by the National Park Service, U.S. Department of the Interior. Created in 1849, the Department of the Interior—America’s Department of Natural Resources—is concerned with the management, conservation, and development of the Nation’s water, wildlife, mineral, forest, and park and recreational resources. It also has major responsibilities for Indian and Territorial affairs. As the Nation’s principal conservation agency, the Department works to assure that nonrenewable resources are developed and used wisely, that park and recreational resources are conserved for the future, and that renewable resources make their full contribution to the progress, prosperity, and security of the United States—now and in the future. A superintendent, whose address is Rt. 1, Box 101, Aztec, N. Mex., is in immediate charge of Aztec Ruins National Monument. [Illustration: The visitor center at Aztec Ruins.]