Meet at the Museum of Natural History's south entrance at 5 p.m. Tuesday, May 22 and be lead on a delightful spring tree tour with CU Sr. Grounds Specialist Alan Nelson who will share the history of CU's "campus" forest. Originally founded on a treeless plain CU now boasts approximately 5,000 trees and 100 different species, many imported from around the world. FREE! Contact: University of Colorado Museum of Natural History, 303-492-6892.