Abstract: A tube-within-a-tube single pole extendable ladder has individual rungs that fold up into the body for portability and minimum bulkiness for transportation. In an exemplary embodiment, the climbing device can be used by hunters. The climbing device has a slender design that is easy to carry through dense underbrush. It is diminutive in appearance while in use. Once mounted to a tree, the main unit can be removed from its harness and transported to another location for use with another harness or removed for security purposes. The telescoping ladder can then be reattached to the tree or other structure simply by mounting to the harness with no tools and retained by a latching component. With the use of a carrying strap, the entire unit, in its closed state, can be transported to the next location and snapped into the provided harness, and is ready to climb.