an intersection with SR 79 Business. SR 79 continues north skirting the eastern edge of town on Pinal Parkway Avenue, meeting both SR 79 Business and SR 287 at Butte Street. This intersection acts as the eastern terminus of SR 287, which provides a direct connection to the city of Casa Grande, SR 87 and Interstate 10. Within the vicinity of Florence, SR 79 services several State, County, Private and Federal Prisons as well as the main offices and courthouses of Pinal County. Directly north of Florence, SR 79 crosses the Gila River and intersects with the eastern terminus of Hunt Highway. The highway then curves northeast through the Florence Military Reservation. After crossing the tracks of the abandoned Magma Arizona Railroad, SR 79 arrives at a diamond interchange with U.S. Route 60 Exit 212. SR 79 continues for a short distance north of the interchange before ending at El Camino Viejo (old US 60) at the unincorporated locality of Florence Junction. The entirety of SR 79 is a direct surface route, roughly paralleling I-10 and serving as the main route through Florence. Florence is the county seat of Pinal County and formerly served the Silver King Mine. Although Florence is not accessible by Interstate, it can be reached by I-10 traffic from SR 287 and SR 87 via Casa Grande and Coolidge. Florence is also accessible from the Phoenix Metropolitan Area by Hunt Highway. SR 79 also serves as a major back-road to the Phoenix and Tucson Metropolitan Areas with control cities along this route showing either Phoenix or Tucson. Though SR 79 does not go to either city, direct connections to both Phoenix and Tucson are provided by SR 77 and US 60. Most of SR 79 is a segment of Historic U.S. Route 80, save for a small section through Florence, where it follows SR 79 Business instead. According to INRIX (a traffic-monitoring agency). SR 79 as of 2011 was the fastest road in the nation, with the fastest 5% of the vehicles using it clocked at an average speed of 88 miles per hour. History SR 79 is a former section of both U.S. Route 80 and U.S. Route 89. Both highways were originally designated along this highway on November 11, 1926. US 80 was the main highway across the southern half of the United States between San Diego, California and Savannah, Georgia, while US 89