Arborists in Bartlett Tree Experts' Portland, OR office are committed to helping local residents and businesses maintain beautiful, healthy trees and shrubs. Collier Arbor Care is now part of Bartlett Tree Experts. From our Portland, Oregon office, we offer professional tree services to the following areas: Portland, Vancouver, Beaverton, Clackamas, Hillsboro, Tigard, Wilsonville, Tualatin, Lake Oswego, West Linn, Oregon City, Gladstone, Milwaukie, Gresham, and Happy Valley.. Cabling and Bracing,Fertilization and Soil Care,Insect and Disease Management,Plant Analysis and Diagnostics,Pruning,Tree Removal