While Sam Peckinpah’s 1972 Steve McQueen starrer “Junior Bonner” didn’t rack up the same commercial success they enjoyed with “The Getaway,” the lyrical rodeo-set family drama’s critical reputation was secured long ago.To mark the pic’s 40th anniversary, fans are gathering this week in Prescott, Ariz., the historic cowboy town that hosted the production during the summer of 1971. The salute to “Junior Bonner,” which also starred Robert Preston, Ida Lupino and Ben Johnson, takes place today and Tuesday at the town’s iconic Palace Bar as part of the annual Prescott Frontiers Day Rodeo. The event was organized in part by “Bonner” screenwriter Jeb Rosebrook, who calls it “a chance to honor those who made my screenplay and so much of my future career possible. It’s an opportunity to thank the town where every location I knew growing up and wrote about, came to life.” Along with Rosebrook, surviving cast members Joe Don Baker and Barbara Leigh will attend the festivities, which include dinner and a screening of the pic. Proceeds from the event will benefit the restoration of Prescott’s historic Elks Opera House.