Mt Whitney Zone Forums The Chat Room Slope Steepness Comfort zones

OK Campers:

Here's another in a series of strange requests. What degree slope are you comfortable traveling on? That is, what slope would you just walk/clamber on without too much thought? At what slope angle do you start getting a little more amped up, but still climb (still 3rd class). And about where does it become 4th/5th class? The last is probably more rock type dependent, but still looking for a slope degree.

What I'm trying to do is create a map layer that reflects terrain that has a high probability of being traveled on over a decade+ time span and slopes that have a lower probability.

This came up in the search for a couple of aircraft that have not been found in about 50 years. I have a semi-coherent theory that in, say, Sequoia Kings, someone has traveled on almost all of the terrain over that time. Certainly almost all easy terrain has been traveled on: flat meadows up to ?? degree slopes. Probably fewer on steeper terrain and then none on almost vertical places. This might be then used to draw high probability areas to search -- the areas that may not have seen much or any use.

I'm thinking of using just 3 slope classes to divide this up.

As a side note, the two aircraft are a T-33 jet that went down in 1957. The canopy was found on Langille/LeConte in 1977 but the aircraft has never been found. The other is a single engine plane that was last known over Merced in the 60s sometime, heading east. That was never found.

So, with huge search areas like that, how do you begin to narrow the probable area to search?

Thought & comments welcome!

g.

Interesting quest!

The tough part about the slope question is that nobody carries a device capable of getting even a close estimate of a slope angle.

I believe that sand or gravel (and likely talus slopes) hang at a 50% slope. That is, two feet horizontal vs one foot vertical. So it is a low angle... somewhere around 30 degrees. But walking on it, most people would estimate it at 45.

Half Dome cables. I've been comfortable walking up the outside first & last thirds, use the cable very lightly in the middle. Rock type is, of course Sierra Granite - the very best.

Walking up the Tombstone Granite inside the cables - No!

So that is probably a good limit value.

Yes, that's the problem I don't have a good feel for degree of slope -- was hoping some of you wizards would.

Half Dome's a good example. I could actually find or calculate the slope -- that's about right for the upper limit of feeling comfortable with friction climbing.

thanks,

g.

I suppose it really does depend on the geology. A 30 degree slope of scree or talus feels like 50 to me. If it's solid, terraced boulders or stone, I would think most non-technical scramblers would venture into as much as 60 degrees, but probably not far.

George, that is a doozy of a project you've got going on! Good luck with it.

That is a hard one for sure when you put it as being "comfortable", for me it's not really a matter of degrees as it's a level of stability such as walking across smooth granite that has water flowing on it and is slick, I have felt uneasy there, or being on steep snow slopes that is very hard packed and I have no gear.

If the question is when would I not do it I guess it's when I honestly feel like I am about to die like I did on Colby Pass, cross country wet muddy scree at about 55 or 60 degrees barely keeping my footing and one slip being fatal, I "reluctantly" turned around lol

It's really amazing that aircraft could go so many years without being found in the Sierra but small aircraft could lodge themselves in any number of cracks in the sides of mountains.

Does this project have anything to do with the Shuttle Radar Topography Mission?

For the US, measurement is about 100' square per point.

I've never measured the slope but I've been up the class 2 route to Lone Pine Peak and wasn't bothered. Coming down was another story...really, really loose.

Also, I feel a lot more comfortable on snow and ice than I do on scree and talus. like crawl from Trail Camp to Trail Crest.

Hmmm...so, when I'm doing all this the airplane is covered with ice and snow.