# Poles of Inaccessibility in the San Gabriels

Joined: 9:35 AM - Feb 12, 2014
So Sean, tekewin and I were talking about what the least accessible location in the San Gabriels would be. It seems like it'd be a worthwhile place to visit if we only knew where it was. Well, wonder no more: http://caltopo.com/m/4N7A

Defining "accessibility" by how close the nearest road/trail is, I ran two computations: one staying away from all roads and trails, and another staying away from roads, but not avoiding trails. Both points appear to be in the vicinity of Ross Mountain. Getting to the main pole doesn't look like it would be too bad, approaching from Ross. It'd be nice to do a through-hike, descending down the East fork from there, but getting down from the pole to Iron Fork looks super steep. In any case, looks like as good a place to visit as any :)

For those who care, details of the computation are here: http://notes.secretsauce.net/notes/2015 ... tains.html

Joined: 7:35 PM - Jan 27, 2010
dima:51320 wrote:For those who care, details of the computation are here: http://notes.secretsauce.net/notes/2015 ... tains.html
Wow... wonderful!

Would definitely be up for a visit to one or both Poles sometime, if you or any other forum members want to make the trip.

Thanks for asking a good question, and even more thanks for carrying out the really nifty analysis to get a definitive answer.  :D

 Posts 791
Resident Trailcam Guy
tekewin
Resident Trailcam Guy
Joined: 11:07 PM - Apr 11, 2013
Dima,

As a computer guy, I am quite impressed with your calculations. Thanks for doing the work. Both points look difficult to reach. The "roads only" one looks like it is in very dense forest.

Joined: 10:35 PM - Sep 27, 2007
That's pretty cool. A cool area as well.

Cucamonga Man
Sean
Cucamonga Man
Joined: 6:32 PM - Jul 27, 2011
That's really cool. Thanks for doing the math. I've been to Ross. Now I guess I need to go back and check out those poles.

How hard would it be to factor in vegetation density? CalTopo stats include Tree Cover and Land Cover. Typically I think it is harder to bushwhack through dense shrub areas than dense tree areas.

Joined: 9:35 AM - Feb 12, 2014
Sean:51350 wrote:How hard would it be to factor in vegetation density? CalTopo stats include Tree Cover and Land Cover. Typically I think it is harder to bushwhack through dense shrub areas than dense tree areas.
Including vegetation density would require significantly more work; at the very least the method I'm using (Voronoi diagrams) wouldn't apply. I do like the simplicity and well-definedness of what I did because if somebody else at some point in the future has this question, they're likely to get the same answer. So when these other people go visit the poles, they'd find the register or whatever else we leave there (maybe somebody already left someting!) Making this more complex makes it more likely that multiple equally "right" answer could exist. If you want to make it more difficult, you can go back/forth several times :)

Stove Droid
Hikin_Jim
Stove Droid
Joined: 3:04 AM - Sep 28, 2007
Ross Mountain?  Iron Fork?  Sounds about right.  "Hmm" said Hikin Jim.

HJ
Backpacking stove reviews and information:  Adventures In Stoving
Personal hiking blog:  Hikin' Jim's Blog

Joined: 6:31 PM - Jul 31, 2011
Thanks for this!  In addition to being interesting, I learned some marketable OSM skillz.

I do notice a couple potential inaccuracies in the OSM dataset in the area.  First, the segment from Lupine to Cabin Flat has been officially declassified as a road (no motor vehicles allowed), but OSM thinks it's a "track" suitable for jeeps.  Second, it lacks the Vincent Gulch trail from Vincent Gap down to the old Mine Gulch site & Cabin Flat.   But that's not the fault of the analysis.

BTW (pardon my googling), we seem to have an undergraduate institution in common.
Slowest_Hiker is in better shape now and actually passes other hikers on the trails.

Joined: 9:35 AM - Feb 12, 2014
Slowest_Hiker:51730 wrote:I do notice a couple potential inaccuracies in the OSM dataset in the area.  First, the segment from Lupine to Cabin Flat has been officially declassified as a road (no motor vehicles allowed), but OSM thinks it's a "track" suitable for jeeps.  Second, it lacks the Vincent Gulch trail from Vincent Gap down to the old Mine Gulch site & Cabin Flat.   But that's not the fault of the analysis.
Yeah, the data isn't perfect, and a lot of time it's not even obvious what "perfect" means. For instance OSM says the trail up the East Fork doesn't go past the bridge. That's not really true, but it becomes much less of a "trail" soon thereafter. So I'm happy with just taking the current results and calling them the true Pole of Inaccessibility. Because I said so :)

Oh, and if you know of a missing trail down from Vincent Gap, you should add it.