A fire is burning in the Santa Rita Mountains south of Tucson near Madera Canyon, the Green Valley Fire District says. The GVFD says the fire ignited Tuesday night and U.S. Forest Service officials are at the scene Wednesday morning and their crews are mobilizing to battle the blaze. According to the U.S. Forest Service, the so-called "Madera Fire" ignited on the western slope of the Santa Ritas between 8:30 and 9 p.m. Tuesday night. It's now four to five acres in size, with around 50 fire personnel responding to the scene. The Forest Service says the Super Trail and the Baldy Trail are closed while crews work to contain the fire.