Gusty winds, steep and rocky terrain, low humidity, and water shortages are slowing the progress of firefighters as they work to contain the Aspen Fire northeast of Tucson, Arizona (red dots southwest of image center). The fire has burned hundreds of homes and other structures in communities on Mt. Lemmon. After beginning on June 17 of unknown causes, the fire had already grown to more than 11,000 acres by Monday, June 23. This image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on June 22, 2003, shows the Aspen Fire northeast of Tucson and farther north, the Picture Fire northeast of Phoenix. [Large image: Fires are also burning in New Mexico (right) and Mexico (bottom).] All active fire locations are marked in red.