Matthew Thomas, supervisor of the traffic enforcement unit at the sheriff's office of PinalCounty, which contains the highest-speed stretch of Route 79.
Border Patrol officers originally spotted the white Ford Excursion around 4:30 a.m. off the side of Interstate 8 in western PinalCounty, about 60 miles south of Phoenix.
But one of the biggest reasons for Phoenix's high pollution levels is actually cattle ranches found south of the city, in PinalCounty and vicinity.. "Those cattle ranches are contributing a lot of fine particle pollution to the small communities near them that are part of the Phoenix metro area, but also to the tribe adjacent to it, " says Nolen.