Located in the White Mountains town of North Woodstock, Lost River Reservation is set high in Kinsman Notch, one of the area’s most famous passes. Located between Mt. Moosilauke and Mt. Kinsman, Kinsman Notch is about 2,000 feet above sea level. Lost River is so-named because the brook draining from the southeast part of Kinsman Notch disappears below the surface in the narrow, steep-walled glacial gorge. The gorge is partially filled with immense blocks of granite, through which the brook cascades along its subterranean course until it eventually emerges and joins the Pemigewasset River. The Forest Society maintains the Lost River Ecology Trail on the Lost River Reservation, which is separate from the gorge area leased to White Mountain Attractions. This trail is free and open to public recreation from spring through fall. The trail is not accessible in winter, when the parking area for Lost River is gated and locked. The trails also close daily one hour before the gorge closes. Dogs are allowed outside the gorge fee area, but not inside it.