Jeong finished three rounds at 13-under-par 203 for a one-shot victory over Mollie Fankhauser and a $9,800 check. She birdied her final hole at Lost Creek Country Club to avoid a playoff.
Fankhauser also shot a 4-under 68 in the final round to finish in second place at 12-under-par 204. Allison Fouch and Lee-Anne Pace fired matching 67s to finish third and fourth, respectively, at 11 under and 10 under.
In-Bee Park, winner of the 2002 U.S. Junior Girls' Championship, carded a 68 and shared fifth place with Song-Hee Kim (70), Danielle Downey (71) and Randi Meadows (68).
Jeong began the final round in first place and held on to her position with a round that included five birdies and just one bogey.
Fankhauser was tied for second place overnight and played bogey-free golf Sunday -- with three birdies on the back nine -- but it wasn't enough. She parred her final three holes.