Thursday, August 17th, through Sunday, August 20th, 2017 10am-4pm. As part of the ongoing campaign to make Ulster the healthiest county in New York, Mohonk Preserve is offering a free, one-month membership for residents of Ulster County. Visitors with proof of Ulster County residency may obtain their passes at the Preserve Visitor Center from 10am to 4pm from Thursday, August 17th, through Sunday, August 20th, 2017, and at the Spring Farm Trailhead from 10am to 4pm on Saturday, August 19th, and Sunday, August 20th, 2017. The membership passes will be valid through September 17, 2017. Passes must be picked up in person, with the exception of minors, whose parent or guardian may pick up a pass on their behalf.