Jocelyn A. Peterson H. Richard Blank Jr. K. Eric Livo Daniel H. Knepper James A. Pitkin Jon E. Spencer Stephen J. Reynolds Michael J. Grubensky Terry J. Kreidler David C. Scott Robert G. Eppinger 1990 application/pdf 10.3133/b1704B en Mineral resources of the Gibraltar Mountain and Planet Peak Wilderness Study Areas, La Paz County, Arizona reports