The frame was covered first with smaller poles, tied with willow withes. The structure was covered with thatch, then earth. A hole left in the center of the covering served as a combined chimney / smoke vent and skylight. The door of each lodge was placed to the east and the rising sun. A long, low passageway, which helped keep out outside weather, led to an entry room that had an interior buffalo-skin door on a hinge. It could be closed at night and wedged shut. Opposite the door, on the west side of the central room, a buffalo skull with horns was displayed. This was considered great medicine.