Since 1968. Casa Grande Cowboy Days and OOdham Tash. There is a carnival the night before the event officially opens. Casa Grande Cowboy Days and O'Odham Tash brought to you by the West Pinal County Mounted Sheriffs Posse - a great week of roping competitions to be held at the Casa Grande Rodeo Grounds, 2525 N. Pinal Ave., in Casa Grande. Cowboys and Indians have been a part of Casa Grande for over 100 years. Come out and join us as we celebrate our rich heritage. Casa Grande will transform into a colorful festival full of Native American arts/crafts, rodeos, and much more! Don't miss the parade in Downtown Casa Grande at 10 am on February 18th or the O'odham Tash Rodeo featuring members of the Ak-Chin, Gila River, Salt River Pima, and Tohono O'odham Nations.