As early as August 16, visitors to Saguaro National Park may observe a low-flying helicopter in route to spray herbicide on invasive buffelgrass in rugged backcountry terrain. We anticipate treating buffelgrass infestations at both the Rincon Mountain District and the Tucson Mountain District. The maps below (click to enlarge) show the general locations of treatments. Last year, approximately 500 acres of buffelgrass infested park lands were aerially treated with herbicide. This included some of the most dense infestations in the southern section of the Rincon Mountain District. Based on the information gathered from monitoring native plants and buffelgrass, there has been a significant decrease in buffelgrass. Even with the success of these treatments, additional treatments are necessary because of the millions of seeds in the soil and the rapid and hazardous rate of buffelgrass spread. The most recent estimate of infested acres at Saguaro National Park is over 2000 acres, and is based on the assessment during the aerial survey in 2012.
In 2014, the National Park Service approved a Restoration Plan and Environmental Assessment including aerial application of herbicide to control invasive, non-native plants in places that are unsafe or too remote for control by ground crews. Ground-based crews will continue to control invasive, non-native plants in accessible areas through manual pulling and herbicide use with backpack sprayers.
Panther Peak in the Tucson Mountain District (west) and multiple locations in the southwestern portion of the Rincon Mountain District (east) and east of the Madrona access point, are scheduled for treatments however, that is dependent on precipitation. Access to the south side of Panther Peak in the Tucson Mountain District (west) and the Tanque Verde Ridge Trail in the Rincon Mountain District (east) will be closed during treatment.
Updates providing locations of daily closures due to aerial spraying will be available on the park’s website: https://www.nps.gov/sagu/index.htm.