Abstract: A shelter of the type having collapsed and expanded configurations. In one of several example embodiments, the expanded configuration includes a tunnel-shaped portion forming a pair of opposing side walls and a roof section. The roof section has a peak positioned above the side walls and the tunnel-shaped portion may include opposing ends with a first opening at the first end and a second opening at the second end, each opening capable of accommodating an end wall. A first sheet is foldable along at least first and second crease lines to define the walls and roof section, the walls having an upper separation distance between the first and second crease lines when the shelter is expanded. The first sheet is segmented into panels with pairs of adjoining panels forming pleats each having a vertex extending from a crease line to an adjoining footing flap, the walls having a lower separation distance between footing flaps on different walls when the shelter is expanded.