Founded in 1995 by Molly and Christopher Barnes, HMI focuses on educating teenagers through interaction with the natural world of the American West and Patagonia, South America.

[1][3] Over that period, Barnes and Peterson conceived of what would become HMI—a college preparatory semester school that incorporates community and wilderness pedagogy central to the outdoor education industry.

[6] The HMI campus has also grown, doubling in size from 40 to 80 acres in 2011, and increasing in number of academic, facilities, and residential buildings.

[13] HMI Semester students partake in two or three wilderness expeditions in the Rocky Mountains of Colorado and the canyons of Utah, specifically Bears Ears National Monument.

[9] While on wilderness expedition, students complete academic assignments, learn backcountry survival skills, and study leadership theory and ethics.

[14] In keeping with the school's philosophy of collective responsibility, students are expected to complete daily chores that include cooking, cleaning, and chopping wood.

Students visit the nearby town of Leadville regularly and participate in volunteer trail maintenance on a local fourteener.