Sinks Canyon State Park Fire Update
In mid July a fire, now called the Fairfield Hill Fire, extensively burned the southeast face of Sinks Canyon. Last week, Steve Bechtel and I (Sam Lightner) were contacted by the Forest Service to assess the damage to the Sinks Canyon climbing area. In a nut shell, what we found was minimal damage to the most popular climbs. However, there are exceptions, and there are potential problems that all climbers should be aware of.
The fire burned along the top of the entire cliff, and near the base of the wall from the Fallen Idol (left side of Hardware Wall) all the way to the very end of the Fairfield Hill crag. In many places it did not burn against the wall. When it did, if the only fuel burned was grass, it was not very hot. There are a few climbs that were seriously damaged by spalling of the rock, and those were climbs where tree's burned against the wall ("spalling" occurs when the water inside the porous rock vaporizes in heat, thus shattering the surface as it expands... see the pictures.) At the Main Sinks Wall, the base of "Billie Idol" has gotten more difficult. Also, "Monkey in the White House" was extensively damaged. The fire managed to miss most other climbs on the Main Wall.
For the most part, this portion of the climbing area seems to have suffered little change. However, we cannot say with certainty that the bolts and rock are completely safe. As always, you must judge yourself if a bolt is safe or not. The biggest danger from the fire will likely be to belayers and people hanging around the base of the cliff. This is because much of the vegetation above the cliff was burned, thus allowing more of the talus and debris above to erode over the edge. We STRONGLY RECOMMEND all climbers wear helmets when at the base of the wall in Sinks (or on any route that is not overhanging).
Fairfield Hill did not fair as well as the Main Wall. Many of the tree's against the Fairfield crags were completely burned, leaving spalling on the wall and potential damage to some of the lower bolts. This is not the case for the entire crag, but is obviously so on many more climbs than the Sinks Main Wall. Climbers going to this area need to be aware that rock fall is a potential, both from the routes and from the slopes above.
They need to also to be aware that some of the bolts may have been damaged. According to our metal engineers, a good rule-of-thumb is that a bolt should not be subjected to a heat greater than that which it was created in. Most of the bolts on Fairfield Hill were forged at around 650F, so the question is, "Was it over 650 degrees at the cliff." The answer is that we have no way of knowing. Certainly, the fire burned this hot and much hotter in places. However, if the only fuel along the base was grass, its unlikely it was this hot at the first bolt of the cliff. Also, it appears the fire burned very fast. In spots we found trees, and even clumps of grass, where the fire partially burned but then hopped onto the next bit of vegetation. This gave the impression that it was burning very fast in high winds. If that is so, then whatever temperature it got to was not held for very long.
If there was a tree against the wall, then maybe it did get hot enough to damage a bolt. Again, we cannot know the actual temperature, and because of that there is no way to know of the potential damage to the permanent protection. You would have to check every single bolt to know this. For Steve and I, we let the spalling be the tell-tale for what WE would do. If the route was extensively spalled, we assume the bolts might be damaged. That's just us. Every climber has to make that decision on his/her own. Fortunately, even at the Fairfield Hill crag there were not that many climbs that were extensively damaged.
So the short of it is that Steve and I felt that 99% of the climbs at the Sinks Main Wall suffered little or no damage, and that probably 80-90% of the climbs at Fairfield Hill were as safe to climb as they were before the fire. However, there is no way to know for sure, and each climber must make that decision independently.
For a bit more information, look through the photos and read the captions. Be safe out there.