"Visitors to Colter's other buildings felt as if they had stepped into another world: that of a hermit, a Hopi Indian, an explorer. At Watchtower, they stepped back in time. With the automobile now a popular form of transportation, Watchtower could be built far from the maddening crowds of the South Rim and Grand Canyon Village, and be enjoyed in relative solitude. Colter knew she wanted to recreate an ancient Indian tower, so she chartered a small plane to spot tower ruins, then rode in Harvy-provided cars to check them out. Her six months of research included extensive visits to Hovenweep National Monument and Mesa Verde National Park, where she found inspiration in the cliff dwellings, particularly Mesa Verde's Round Tower of Cliff Palace.

She sketched out the plan and built a clay model. A 70-foot wooden tower was constructed at the site, so Colter, now in her sixties could climb to the platform to make sure the site and height were correct. While the tower's inspiration was ancient, the tapered cylinder was built over a steel-frame structure on a concrete foundation. Local rock created a richly textured surface."

-from chapter two, Mary Colter Arrives