The Okmulgee Pecan Festival runs every June over a long weekend on the downtown square in front of the Creek Council House. It celebrates the pecan orchards of central Oklahoma with a parade, a carnival, a stage of country and gospel acts, several thousand dollars' worth of pies and brownies for sale, and a regular attempt at one or another "world's largest" pecan-based dish.
The crowd is mostly local, with a strong showing from across the Muscogee Nation. It is a good time to be in town if you want a sense of Okmulgee on a busy weekend. Practical note: hotels in town fill up — book ahead, or stay in Tulsa and drive down.