The inventive concept is a safety device, which is a two-part emergency safety harness constructed so as to be clamped to a climbing tree stand typically used by an outdoorsman, particularly a hunter. The objective of the device is to safely expedite the vertical positioning of a tree mounting strap during ascent and/or descent of a tree. This is accomplished by means of symmetrical left and right assemblages of rigid mounting arms, brackets, and retention clasps which, when combined, hold a the tree mounting strap loosely around the circumference of a tree trunk. Should the climber experience an imminent fall from the tree, the arms of the safety device will cause the un-tensioned tree mounting strap (to which the hunters body safety harness is attached) to collapse against the tree trunk. This tightening action will arrest the fall immediately and prevent serious injury.