Erin Birgy was born in Idaho in 1988 or 1989.[1] She kept horses as a child and was part of a traveling rodeo, in which she practiced barrel racing, calf roping and mutton busting.[1] In her teens she moved to Spokane, Washington, then Olympia, Washington.[1] Birgy took on the name Mega Bog in around 2009,[4] having previously performed under the names Little Swamp and Midi Marsh.[1] In 2019 she and James Krivchenia of Big Thief moved to Los Angeles, then to an off-grid cabin in New Mexico.[1]