Established in 1921 by educator Donald Slesinger, Camp Treetops enrolled boys and girls of young age and diverse backgrounds at a time when most camps were segregated by gender, race, and religion.

In 1926, Helen and Douglas Haskell joined the Camp staff and three years later were appointed directors. For the next 40 years, the Haskells shaped Treetops in accordance with values influenced by John Dewey’s progressive views of education—notably that too much structure and competition stifled children’s natural curiosity and creativity. As a result, Treetops campers, then as now, awoke every morning not from a call of reveille but from a counselor’s gentle nudge; they dressed not in uniforms but in their own clothes, often going barefoot. To foster independence and self-confidence, campers helped choose their activities and plan their own days, performed daily work jobs, and slept in quarters apart (but not far) from their counselors.

In 1938, Helen’s sister and brother-in-law, educators Leonora and Walter Clark, opened North Country School on Camp property to extend Treetops’ ideals to classroom learning. Ever since, Camp and School have operated in tandem, sharing facilities, a guiding philosophy, and a single Board of Trustees instituted with the reorganization of the two programs into one non-profit in 1957.