Keyhole Sink #114 & Oak Hill Snow Play Area


Keyhole Sink Quick Guide

Distance: 1.3 miles

Elevation Gain/loss:

Type: Out and back

Difficulty: Easy

Location: 35.2700, -112.0144

Family Friendly: Yes, all ages

Dog Friendly: Yes, on a leash

Shade: Yes

Fee: None

The San Francisco Volcanic Fields have 600 remnants of tectonic activity visible today throughout the Flagstaff area, and the keyhole sink is one it’s geologic features. Keyhole Sink is 1.3 mile out and back trail that features a ponderosa forest, seasonal waterfall, wildlife, and 1000-year-old petroglyphs. Parking for the keyhole sink is located at the Oak Hill snow play area. The trail is accessed by crossing Route 66 and through a green gate in the fence line.


Our Hike

We made an error heading south from the parking lot following the trail to the snow play buildings. We found it quite unusual that there was no signage for Keyhole Sink within or around the Snow Play Area. After backtracking to the parking lot we spotted the green gate across the road. The trail starts through the gate and follows the blue blazes marked on the trees in very consistent intervals. During the winter the trail is used by cross-country skiers resulting for the need for a well-marked path, as fresh snow could easily cover the markers to make the trail a bit of a conundrum.

The trail is an easy stroll following a gentle incline past some volcanic rock outcrops . We continue to follow the blue blazes as the sound of the road disappear and the sound of the howling wind through the forest takes over. The canyon begins to converge into a box canyon and the towering Ponderosa Pines closing in indicate that we are near Keyhole Sink.

After a short .6mi in we came to a fenced in area with a guest register and interpretive sign. The sign features the aforementioned petroglyphs showing deer entering into the box canyon with hunters ready to strike at the cliff tops. The dark basalt cliffs act as a giant catchment basin funneling snow melt and rainfall into a dammed box canyon. This location has been a reliable water source for wildlife across the millennia. As a result, this location has served another purpose, a dependable ambush site for predators.

There is also a sign posted as a reminder of the effects of senseless vandalism on our ancient heritage. 2010 the petroglyphs were defaced by low lives who drew on the petroglyph panels with aluminum roofing cement. The vandalism made national news and an expert from Atlanta, was recruited to help repair the site. They were able to remove most of the evidence of the vandalism, and now hidden cameras monitor the site.

After signing the guest register we passed through the gate entering the Keyhole Sink. Due to a very dry monsoon season there was no water or wildflowers in Keyhole Sink.

There is easy access to the top of the dark basalt cliffs when exiting the enclosed area, follow the slight trail along the wooden fence line to the north through the aspens. From this vantage point one can survey the entire Keyhole Sink area. One can imagine what is was like waiting from the cliffs for a deer or elk to enter the Keyhole sink...


Oak Hill Play

The Oak Hill Snow Play Area is located on the site of an old alpine ski area that operated during the 1950s. There are two separate sled runs one is 400’ and the other is 900’. There is a warming shelter at the bottom of the hill with a fire circle. Toilet facilities are available at the parking lot.


Special considerations:

According to the Forest Service the brown dog tick (Rhipicephalus sanguineus) may be present in this area. The Brown dog tick can transmit Rocky Mountain Spotted Fever.

When you visit remember to leave no trace, and do not disturb the native heritage. Leave this beautiful place better than you found it. Treat this natural treasure with the care it deserves! Warning⚠️

Hiking and outdoor related sports can be dangerous. Be responsible and be prepared for the trip. You are only as strong as the weakest person in your group. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water, more than what you need. Make an itinerary with your plan(s) and leave it with someone you trust. Our hiking guides are not a replacement for common sense.


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