The first, a desert grassland site 90 km south of Albuquerque, on the Sevilleta National Wildlife Refuge
, Socorro County, New Mexico, USA (34[degrees] 21.3'N, 106[degrees] 53.1'W, elevation 1,465 m), was dominated by one-seed juniper (Juniperus monosperma), honey mesquite (Prosopis glandulosa), and various desert grasses (Sporobolus spp.
Wolves that are candidates for reintroduction undergo a "pre-acclimation" period at Sevilleta National Wildlife Refuge
in New Mexico and other remote facilities, where wolves can be held and managed to foster behavior that will enhance their ability to survive in the wild.
Parmenter and his coworkers at the University of New Mexico in Albuquerque had been counting populations of rodents at Sevilleta National Wildlife Refuge
, some 50 miles south of Albuquerque, since 1989.