Spring equinox is marked by the movement of a beam of light on the north wall of the rock shelter. As the sun rises toward solar noon, the beam of light climbs up a flaked crack in the north wall.

Twenty-eight days later, the same light spot shines on the floor of the rock shelter.

This series of pictures follows the beam of light from the day before spring equinox until twenty-eight days after. All pictures were taken about solar noon.

Just above the first seven in the caption 4/17/97 a small spot of light can be seen on the floor of the rock shelter.