Up on the Mountain follows Southeast Asian refugees, Latino immigrants, and rural Americans on a year-round migration to harvest wild mushrooms from public forests in the American west. Working on foot, equipped simply with a bucket and a pocket knife, harvesting mushrooms is an accessible way for the pickers to become their own bosses. But despite evidence of the sustainability of the harvest, the workers who supply the restaurants and markets of Europe, Japan, and North America are repeatedly denied access to public lands.