The Natrona and Kelly Walsh volleyball teams swept Green River and Evanston over the weekend, headed into this weekend Casper Invitational at the Events Center. Kelly Walsh defeated Green River 3-0 and Evanston 3-2 to improve to 14-1 on the year. Natrona beat Evanston 3-2 and Green River 3-0 to advance to 12-3 on the season. The Casper Invite begins Friday and concludes Saturday at the Events Center.