Eighty-three players competed for two qualifying spots for a trip to the championship proper which will be held Aug. 9-15 at Oakmont Country Club in Pennsylvania.
Ziegler, from Tualatin, fired a first-round 66 and followed that up with a final-round 69 to win the competition by two strokes. It marks the fifth time that he has qualified for this national championship.
Ziegler jumped out to the early lead and never looked back, registering five birdies – offset by one bogey – in shooting 4-under par for the opening 18 holes.
Moir, of Lake Oswego, made birdie on the first hole of a four-player playoff to secure the second spot. Moir carded the low round for the event shooting 5-under par in his final 18, a round that included an eagle on Hole No. 1 to accompany five birdies.
Collin Hodgkinson and Zach Foushee finished as first and second alternates respectively.
The next USGA qualifying events are for the U.S. Senior Amateur and U.S. Senior Women’s Amateur with those being held Aug. 4 at Columbia Edgewater Country Club in Portland.