Supervisor Pete Schabarum will lead equestrians Sunday over the recently completed Bonelli Loop Trail on the northern shore of Puddingstone Reservoir as part of the fourth annual Pete Schabarum-Walnut Creek Trail Ride. The Los Angeles County Sheriff's Passe and the Bonelli Park Mounted Assistance Unity will co-sponsor the event. The ride will start at 10 a.m. in the Bonelli Park picnic valley and follow the Walnut Creek Trail to the new Bonelli Loop Trail for a formal dedication ceremony. The new trail, about two miles long, connects with other trails to complete a circle of the regional county park in San Dimas. The ride is open to all equestrians. Rental horses are available at the park.