Abstract The carbonatite complex at Iron Hill is located southeast of the town of Powderhorn along Cebolla Creek, Deldorado Creek, and Beaver Creek in Gunnison County, Colorado. To reach the complex, travel 9 mi (14.5 km)west of Gunnison on U.S. 50 to the intersection with Colorado 149, turn south on Colorado 149 and travel 15 mi (24 km) to the intersection with Cebolla Creekroad; turn southeast on Cebolla Creek road; after about 2.5 mi (4km), the outcrops on the left are in the carbonatite stock of the Present address: Department of Geology, Adams State College, Alamosa, Colorado 81102 complex. Roads to the east off Cebolla Creek road along Deldorado Creek and Beaver Creek connect with a variety of dirt ranch roads that provide excellent access to the rocks of the complex.These roads are periodically maintained by Humphreys Mineral Industries, Inc., of Denver, Colorado, the property managers.Therefore, most of the complex is easily accessible by short hikes from roads navigable by most vehicles. A number of patented mining claims exist in the area, but permission to access the property has never been denied. The geologic map of the complex(Fig. 1) is located within the Rudolph Hill Quadrangle(Olson, 1974) and within the Powderhorn Quadrangle (Hedlund and Olson, 1975).Access roads are also shown on the Rudolph 325 Hill and Powderhorn 7.5-minute quadrangles (1:24,000). Some of the better localities at which to see specific rock exposures are shown on Figure 1.