CU Museum of Natural History and Facilities Management will be hosting their annual Spring Campus Tree Walks with Arborist Vince Aquino and Alan Nelson, retired Outdoor Services director. Two tours will be offered: the first from 5 to 7 p.m. on Tuesday, May 16, and the second from 5 to 7 p.m. on Wednesday, May 17. Rain or shine. Tours are free, open to the public and will start at the south entrance of the CU Museum of Natural History at 15th and Broadway. Reservations are not required. All ages are welcome.