Letter from Carl T. Hayden to Michael J. Riordan explaining the benefits of selling Bright Angel Trail and building an approach road.

Letter from Michael J. Reardon to Carl T. Hayden, in agreement with Ralph Cameron, asserting that Bright Angel Trail should not be sold from Coconino County to the United States.

Plan of Babel IIB Arcology city structure design by Paolo Soleri, from 1970 exhibit at Corcoran Gallery of Art, Washington, DC

Interior photograph of Solimene ceramics factory in Vietri sul Mare, Italy showing concrete pillars supporting the roof

Interior photograph of Solimene ceramics factory in Vietri sul Mare, Italy showing staircase

Model of Arcosanti Arcology city structure design by Paolo Soleri, from 1970 exhibit at Corcoran Gallery of Art, Washington, DC

Model of Arcosanti Arcology city structure design by Paolo Soleri, from 1970 exhibit at Corcoran Gallery of Art, Washington, DC

Plan of Logology city structure design by Paolo Soleri, from 1970 exhibit at Corcoran Gallery of Art, Washington, DC

Model of Arcosanti Arcology design by Paolo Soleri

Model of Babel IIB Arcology design by Paolo Soleri at an exhibition