The City of Cheyenne will celebrate its 33rd Arbor Day at 11 a.m. on Thursday, May 21 at Saddle Ridge Park. During the ceremony, winning tree poems from third grade students at Saddle Ridge Elementary will be read by the winning students, an update on the Saddle Ridge Park development plans, Tree City USA and Growth Awards will be announced and Mayor Rick Kaysen will read an Arbor Day Proclamation.