Held annually since 1995, the Tucson Marathon has grown from roughly 800 to over 4,000 participants, starting near Biosphere 2 in Oracle and finishing at Pima Community College's Northwest Campus near Oro Valley. The net-downhill course is a consistently ranked Boston Marathon qualifier, with a notably high share of finishers hitting qualifying times. The event also offers half marathon, 50K, and relay options through the scenic Catalina foothills.