Runners make their way along an almost all downhill course in the 13.1-mile race at the Holualoa Tucson Marathon, from its starting line just north of the Tucson metropolitan area to the finish line at the Golder Ranch Fire Station, just off Golder Ranch Road.
Runners start this point-to-point race — which is run entirely on paved surfaces, largely along Arizona Highway 77 — on Biosphere Road, just a short drive from Biosphere 2, the Earth science research facility that’s an entirely closed system in the Arizona desert, where researchers study farming and technology and humans’ interaction with nature.
