From Wikipedia, from the book Interlochen, The First 25 Years:
In 1926, Joe Maddy was asked to organize and conduct the First National High School Orchestra for the Music Supervisors' National Conference (now known as the Music Educators National Conference) in Detroit. Its resounding success led to an invitation to duplicate the experience at the Dallas, Texas convention of the National Education Association's Department of Superintendence in 1927. The exuberant young musicians pled for the chance to work and play together longer than the few days the convention appearance afforded. Joe Maddy promised them a music camp!
In June, 1928, at Interlochen, Michigan, in the midst of a magnificent stand of virgin pine trees between two lovely lakes, The National High School Orchestra Camp opened its doors. On leased land, with the old Hotel Pennington, several cottages, 29 new camper cabins, a hospital, water and sewer system, the new Interlochen Bowl, and $40,000 debt, this brave experiment was launched.
From the Web Site
Since 1928, Interlochen has offered an immersive arts experience that fosters a sense of closeness discovered only through a deep, shared appreciation. Generations of artists and arts enthusiasts have experienced the special and intangible magic that transpires on Interlochen's beautiful campus, nestled between two pristine lakes and surrounded by quiet pines in northwest Michigan.
A true artist's retreat, Interlochen invites students grades 3-12, as well as adults of all ages, for once in a lifetime arts education programs designed to hone their skills and nurture their humanity. The depth and breadth of our offerings is unmatched. Our community transcends backgrounds and beliefs, borders and barriers: here, we are united through the universal language of the arts.
Our umbrella organization, Interlochen Center for the Arts, encompasses six distinct program areas, each founded to propel arts education and engagement: Interlochen Arts Camp, Interlochen Arts Academy, Interlochen Online, Interlochen Public Radio, Interlochen Presents, and Interlochen College of Creative Arts.