The Deer Lake property dates to 1662 when Samuel Buell bought 250 acres from Mohegan Chief Uncas' second son, Owaneco. The two-story wood-framed house at Deer Lake was built in 1815, probably by a member of the Buell family, while the lagoon, which is used by the summer camp for swimming and boating, is a kettle lake formed by glaciers. It was dug in the 1700s to feed the races of the Elba Paper Mill, for which the road is still named.

In 1930, the property (which was then called Allison's Pond) was held by Henry Opp, who also owned Madison Lumber and operated an illegal still on the premises which was seized by revenuers. He then sold it in 1933 to Ralph and Elizabeth Hill, who were looking for a home for her mother, dammed the river and renamed the newly flooded valley Deer Lake .

Inspired by working at a summer camp in Massachusetts, the Hills in 1933 opened their own camp on the property, with 12 campers, little money and cabins they built themselves. They also insisted that it be racially integrated, as Ralph Hill "always held that all races are equal."

Now, there's an intriguing twist here. Ralph Hill reportedly was the inspiration for the character Dr. Doolittle, created by author Hugh Lofting, who lived down the road from Deer Lake. Hill was known to leave scraps of food for the local wildlife, who sometimes followed him as walked the trails of Deer Lake. He and his wife owned the property until 1959 when they sold it to the Boy Scouts, who made it available for their troops on weekends and for the public who were invited to attend summer camps and town events.

In 1978, the Scouts hired Mark Clifton as a volunteer and, four years later, elevated him to a paid employee. Clifton and wife Patty, whom he married at Deer Lake, maintained the grounds, ran programs and restored the property's original buildings. They also ran the summer camp, taking it over from local YMCAs and the Shoreline Foundation.

The Cliftons stayed on the property until it was bought from the Boy Scouts in September, 2022, by Pathfinders, Inc., a local non-property dedicated to preserving it as open space. The cost of the transaction was $4.75 million, with all money raised by Pathfinders in an ambitious fundraising effort in what U.S. Sen. Richard Blumenthal described as "a profoundly important moment."

Pathfinders maintains the property today.