Benson is a city in Cochise County, Arizona, in the United States, 45 miles east-southeast of Tucson. According to 2006 Census Bureau estimates, the population of the city is 4,934. The city was founded in 1880 when the Southern Pacific Railroad came through. It was named after Judge William B. Benson, a friend of the president of the railroad. The city is perhaps best known as the gateway to Kartchner Caverns State Park.