Abstract: A portable apparatus for climbing a tree, pole or the like includes a housing with a tree engaging face and a step, a line carried on the housing, and a reel. The line is movable between a retracted position wherein the line is contained within the housing for storage and transport and an extended position wherein the line is attached to the housing on the tree for climbing. A distal end of the line includes a latching block. The latching block is received and retained within a latching slot in the housing after encircling the tree or pole with the line. A biasing spring connected to the reel mechanism assures the take-up of any slack in the line. Following the take-up of slack, a locking pin is moved along a guide track in the housing until it engages a locking slot in the reel. The pin and slot cooperate to maintain the reel in position, thereby positively preventing the paying out of line and allowing safe tree climbing by stepping on the device.