Howland completed her first tour win at The Wetlands at 11-under-par 205.
Mollie Fankhauser fired a 6-under 66 in the final round to take second place at minus-10. Seo-Jae Lee shot 68 to end alone in third at 9-under-par 207.
Jenny Gleason, who shared the second-round lead with Howland, managed just a 1-under 71 to slip into a share of fourth at minus-8. She was joined there by Liz Janangelo.
Howland, who collected $10,500 for the win, traded a bogey for a birdie from the fourth to go with seven pars on the front nine. Around the turn, she dropped in back-to-back birdies from the 11th to move to 9 under.
The 29-year-old dropped a shot on the 13th, but closed with three birdies over the final four holes to secure her first tour victory.
Allison Fouch and Ha-Na Chae shared sixth place at 7-under-par 209.
Kim Welch fired a course-record, 7-under 65 Sunday to jump from a share of 47th into a tie for eighth at 6-under-par 210. She finished alongside Kim Brozer, Jane Park, Lynn Valentine and Jessica Shepley.