Lost River Cameras. Lost River Reservation The Lost River Reservation is a protected area with a series of caves along a gorge in the White Mountains in Woodstock, New Hampshire, United States.Located 5 miles west of the village of North Woodstock on New Hampshire Route 112, Lost River … Sold - 760 Lost River Rd, Easton, NH - $455,000. Very informative plaques placed all over the different trails, leading up to a well-equipped gift shop wit, Got deal through Groupon and decided to it might be a fun day trip for the family. The river flows southeast from Kinsman Notch to Jackman Brook, where the two streams form Moosilauke Brook, which continues northeast through the granite gorge of Agassiz Basin and joins the Pemigewasset River in the village of North Woodstock. 1 Reviews (603) 745-5044 Website.