Hard to reach Trees, Climbing Specialists Climbing and working in trees demands specialized equipment and skills. The potential for a serious injury or fatal fall is always present, so employees must be well trained and certified before they perform tree climbing work. Now that National Program direction has been issued, all Forest Service tree climbers will have to be trained and certified through Dorena or other recognized training source. But no amount of reading can make a person a safe and efficient tree climber, that takes proper training and practice. See why we will make a difference for you!