Dinosaur national monument Charlie and Evelyn Mantle live on isolated ranch in Yampa valley, Dinosaur National monument. Desert v.20 #5 May, 1957 p.4 New development program that will soon begin by the government. The Living Wilderness Winter-Spring 1958 v.22 #63 PP-30-32 Details of new dinosaur exhibit to be opened June 1. Post May 22, 1958 p.19 c.5-8 Biography of Jess Lombard, the superintendent; material included on the future of the monument. Post May 2b, 1958 p.24 c.4-b