Sun Keeps Time on the Walls of Chaco Canyon

A day at Chaco Canyon, where the sun keeps time on the walls of the ancient great houses.

Nell Sorensen 5 min read

5:40 a.m.

Pueblo Bonito is dark against the talus slope, and the sky to the east is just beginning to lighten. The air over the canyon floor is cold and still. The canyon is wide here, and the north cliff rises high above the ruin, a darker wall against the sky. The ruin is a long mass of low walls and fallen stone, its shape hard to read in the gray half-light. In the gray it looks natural, part of the slope; only the straight lines of the standing walls give it away. No wind moves in the wash. The rims of the canyon are black lines against the growing light. The first birds call from the rocks above the ruin, brief, single notes. Fajada Butte stands black at the mouth of the canyon, banded with ledges, between the two rims. The sky beyond it turns from gray to a pale, thin yellow, and the stars overhead go out one by one. The walls of Pueblo Bonito hold only the cold of the night.

7:25 a.m.

The sun clears the south rim, and the light is low and long across the canyon floor. It reaches the great houses along the north wall in order — the east ends of the room blocks first, then the long south faces, course by course, as the sun climbs. The walls, built of tabular sandstone laid flat in beds of mud mortar, are thicker at the base than at the top, and the low light rakes the surface so that every course is visible. The stone is the color of the soil — gray, tan, and in places a faint rose. The standing walls glow against the blue shadow of the cliff behind them. The T-shaped doorways open dark on the lit face of the masonry. The plaza bounded by the room blocks fills with sun. Across the wash, Casa Rinconada's round wall is still half in shadow. The shadow line retreats down the face of the north cliff, and the walls stand clear of it.

The great kiva of Casa Rinconada, its circular wall and floor vaults

9:20 a.m.

By 9:20 the sun is high enough to light the full face of the masonry, from the base of the wall to the top. The sandstone warms from gray to tan. The south wall of Pueblo Bonito takes the light square-on, and every course of stone reads clearly against the next. The mortar between the slabs is the same color as the ground under the ruin. The rear rooms rise against the cliff, their upper stories still in the full sun. Between the ruin and the cliff, the fallen stone lies in long mounds. The plaza is bare earth, packed hard, with the round stone lips of the kivas breaking its surface. Ravens cross the canyon from the south rim, riding the first heat of the morning. The shadow of the north cliff pulls back to the base of the talus. The doorways of the ruin are the only dark places on the wall. The air over the plaza shimmers where the stone gives off its heat.

Noon

At noon the sun is at the top of its arc over the middle of the canyon, and the walls lose their depth. The raking light is gone; the masonry flattens into a single pale band under the cliff. The sandstone is bleached toward white, the color of the canyon floor. The doorways hold their black shade, and the kivas hold theirs. The wash lies pale through the middle of the canyon, a strip of bare sand dividing the north side from the south. The shadows are gathered at the bases of the walls, small and tight. The air is still, and the canyon is quiet enough to hear grit settle. A lizard runs across the face of the wall and stops where the shadow of a doorway cuts the stone. The ravens sit on the wall tops, wings closed. The sun presses straight down, and the shadow of the south wall is thin against the ground at the base of the masonry.

2:30 p.m.

At 2:30 the light begins its shift to the west. The east ends of the room blocks are flat and gray, while the western rooms of Pueblo Bonito catch the full force of the sun. The sandstone turns from tan to amber. Kin Kletso, standing square on the canyon floor to the west, is lit across its whole western face. The shadows begin to grow, reaching out from the eastern corners of the walls. The slanting light brings back the texture of the masonry; every slab and every patch of mortar is visible on the lit faces. A wind comes up the canyon, dry, carrying grit, and moves across the tops of the standing walls before going quiet in the plaza. It comes and goes in gusts. The east end of the south wall goes gray, and the west end is still lit.

The walls of Kin Kletso great house with the canyon rim behind

4:45 p.m.

The shadow of the south rim reaches the foot of the great houses. The lower courses of Pueblo Bonito stand in blue shade, while the upper stories still hold the western sun. The line between shade and light climbs the sandstone slowly. Above the line the wall goes orange, then rose, and the cliff behind the ruin is the same color. The light passes through the empty doorways of the upper rooms and lays bright shapes on the stone behind them. Chetro Ketl, west of Pueblo Bonito, is crossed by the same line of shade. The canyon floor is fully in shadow, and the wash is a gray band between dark walls. The wind drops, and the air cools at the base of the wall. The top courses of the wall burn red against the evening sky, and the lower courses sit in the dark.

Dusk

The light is gone from the canyon floor. The last of it holds on the top of the north rim, then that goes too. The walls of Pueblo Bonito pass from rose to gray and into a single flat dark. A band of pale green holds in the west above the rim, and the first stars come out over the south side of the canyon. The air turns cold, and the stone gives back the heat it gathered in the day. The ruined walls no longer read as masonry; they are only a dark step in the slope. The back wall of Pueblo Bonito runs along the base of the cliff, and the south wall curves around to meet it.