American Alpine Jounrna and Accidents in North American Climbing

Rappel Error—Anchor Failure, Arizona, Sycamore Canyon, Paradise Forks

  • Accident Reports
  • Accident Year:
  • Publication Year: 2006


Arizona, Sycamore Canyon, Paradise Forks

On November 5, Shelley Windsor (31) had been climbing on several routes at Paradise Forks, Sycamore Canyon with her climbing partner Mark Brenner (26). During the climbs and rappels, the anchors had been constructed on large, live pine trees with one-inch nylon tubular webbing slings, connecting the end loops of the slings with a carabiner that was then attached to the rope.

Prior to the accident Mark led a climb and then belayed Shelley up the same climb. Upon reaching the top of the climb, she disconnected, then pulled the rappel rope and retrieved the anchor slings from the rappel anchor tree. She then took the rope and the anchor material to a different tree in preparation for a rappel to end up where their backpacks were. She constructed a new anchor around a large, live Ponderosa pine tree (approximately six feet six inches in circumference and approximately 31 feet from the cliff edge) and was preparing to rappel as Mark walked toward her after packing his gear from the previous climb.

When Shelley began to weight the rappel, Mark saw the anchor come apart. The slings were no longer attached to the tree. Shelley fell approximately 90 feet to the canyon floor.

Other climbers in the area were notified of the accident and one of them made a call for help. Bystanders did an assessment and began first aid while waiting for rescue. Due to the relative remoteness of the area (approximately 20 miles from the nearest EMS units and approximately 40 miles from Flagstaff), rescue units had a significant response time to the scene.

After being extracted from the canyon, Shelley Windsor was transferred to an air ambulance and flown to Flagstaff Medical Center where she was pronounced dead.


Ms. Windsor was wearing a commercially sewn seat harness and a helmet at the time of the accident. She used an ATC-type rappel device, according to Mr. Brenner. The climbing rope appeared to be in good condition and the webbing found at the bottom of the cliff was in good condition and was still tied into a sling. The auto-locking carabiner appeared to be in good condition other than some minor damage from the fall.

The two slings (described by Mr. Brenner as ten-foot runners when tied —but possibly longer) used for the anchor were the same color. This could have caused difficulty in inspecting the set-up.

It appears that Ms. Windsor may have intended to girth hitch two slings together and subsequently wrap the linked runners around the tree, but somehow an error was made in the connection, and when weighted, the slings came apart. One possibility is that the girth hitch was tied around a bight of the second sling and not through the sling. In this configuration, it may appear that the slings were connected correctly and would bear some weight if tested without full body weight prior to the rappel. Once full body weight was applied to the system, it could fail. Another possibility is a knot-jam, which could have been caused by the knot of one runner being pinned against the tree trunk by the bight of the other runner under tension. This configuration might initially bear some weight but could also fail after repeated loading and unloading associated with the edge transition during rappel.

To reduce the likelihood of a similar incident from occurring, a suggestion is to use a more easily inspected anchor system when wrapping trees, possibly incorporating different colored slings if connecting them together is foreseen. It’s always a good idea to have one’s partner inspect the system. (Source: Aaron Dick, SAR Coordinator, Coconino Country Sheriff’s Office, Jed Williamson, and local climbers)

This ANAM article has been reformatted into HTML. Please contact us if you spot an error.