Rosswell Sinclair of Albuquerque, New Mexico, won the two-day event at the University of Wyoming's Red Jacoby Golf Course with an 8-under 134. Sinclair qualified for the U.S. Amateur Championship on Aug. 13-19 at Pebble Beach, California.
Murdock, who will be a senior at UW, finished two strokes back with a 6-under 136 and Costello, who will be a sophomore at the University of Utah, shot a 4-under 138. Murdock and Costello are the first and second alternates, respectively, for the U.S. Amateur Championships.
Also for UW, Dan Starzinski tied for fourth with a 3-under 139, Jared Edeen (Cheyenne) tied for 11th with a 4-over 146 and Kirby Coe-Kirkham (Sheridan) tied for 20th with a 9-over 151.