The mountains, stripped naked

[dima]

Yall may have heard of lost cities being found in the Central American jungle using LIDAR scans. If not, go look that up right now! An airplane flies over the jungle, and uses a laser scanner pointed at the ground to measure lots and lots of distances. Most of the laser returns come from the trees, but a small number reach the ground. You can write a computer program to process the points to strip out the returns from the trees, to then get a view of the bare ground. In the case of jungle cities, this would uncover rectangular structures that were parts of the ancient buildings. Somebody then bushwhacks to that spot to find the lost city, and declares victory.

Anyway, that's all cool, but not particularly new or relevant to us. But. Today I found out this data exists everywhere, including in the San Gabriels, and we can look at our local mountains to see, at the very least, old abandoned roads. For instance here's an old, very abandoned logging road North of ACH by Little Jimmy:

I've found this previously, and it was my super secret camping spot until the Bobcat Fire burned down that part of the forest. It's on OSM because i added it years ago:

https://caltopo.com/map.html#ll=34.3570 ... &z=16&b=om

It's hard to see in the imagery, but is crystal clear in the LIDAR scans. This is accessible in a few places. Most of the servers are slow, but it's usable:

- https://elevation.nationalmap.gov/arcgi ... mageServer
- https://apps.nationalmap.gov/3depdem/
- In the JOSM tool

Some notes are here. So far I see a LOT of old logging roads around the crest and Pine Mountain area. Lots of stuff around HWY 2 in general (check out Dark Canyon)! You can clearly see the switchbacks coming down from Muir Peak to West Fuji. And so on. What can yall find? I think there's much informed bushwhacking in our future.

[dima]

jeko1034 pointed out to me that caltopo has this in the "Shaded Relief" layer. And it does, but it's not as good, and is missing a lot of stuff. Poking around just now I've found lots and lots of stuff: some stuff is still sorta there, and some stuff isn't at all.

Trail from Allison Mine to Stanley-Miller: gone. Trail from Bichota canyon to Rattlesnake peak: mostly there! PL&P: mostly there. There was apparently a road from near Allison saddle directly down to Coldwater canyon (to "Weber camp"). You can clearly see the cuts at Widco mine and various trails around there-ish and bighorn ridge. The ridge from Las Flores Canyon up to the paved Mt Lowe road now has a good use trail that goes straight up. But apparently there were (and still are!) lots and lots of nice switchbacks along the whole route.

I'm going to stop poking at this now. Tell me what yall find!

[Nate U]

Yeah its the same idea as the CalTopo shaded relief, or Google Maps Terrain shading, but this does seem a little high resolution. Nice find! Maybe useful for old mine stuff?

[dima]

There are a TON of roads/trails that I didn't know existed. Also, I've traced the full PL&P run: from Doe flat to Fish Fork Camp! The upstream end of that probably isn't completely overgrown, and I'd be interested in hiking it.

[dima]

More finds.

• There's still a level trail from below the lower Baldy ski lift to the ski hut, that more or less follows the 8000ft contour.
• There's a trail to the Gold Ridge mine. Branches off at 7500ft, and stays mostly level to San Antonio Canyon. Then follows a gully up on the other side of the creek.
• There's an old road between the Arroyo seco and the ACH from Twin Canyon ridge all the way to Dark Canyon. It connects to the furthest back section of Dark canyon road. Today it's a short section between the descent from CCC ridge and Dark Canyon trail, but it actually continues and goes a long way S.
• There are some roads/trails E of Santa Anita Canyon, just N of where the E Fork comes in. Starts by the cabins just below Sturtevant Falls, and switchbacks up to the E. Goes up over the saddle, fork goes to the high point, but the main route continues N, an eventually drops back down to the river
• A long well-preserved trail still exists, running from the East Fork, up Williams Canyon (starts E of it, then crosses over to the W), runs up to the saddle NE of point 3261, then keeps going to connect to the E/W trail that becomes the mostly-intact PL&P trail.

[Sean]

Lidar is pretty cool. A member of my trail crew showed it to me a couple years ago when we were poking around in Dark Canyon. I assume you're talking about the old Edison road that they built to cross the canyon before the highway was constructed.

While a lot of defunct trails show up on lidar, they have been consumed by brush or segmented by shelf failures at cliffy sections.

[dima]

I don't know if this is the "Edison road", but if that's what predated hwy 2, then it's probably it. Here's the view:

The roadbed is mostly there all the way to the ridge nest to Twin Canyon (the bottom of the image). Below that recent road-building work covered it up.

[Sean]

Yes, the Edison road predated the ACH. It was built in 1925 as part of the Vincent Transmission Line project. We still use part of it to descend into Dark Canyon from the CCC ridge.

[Sean]

Back in the old days I believe it was Lucky Baldwin who thought about sending a railroad through Santa Anita Canyon. He built a trail through there but never got it to railroad grade. Maybe you're seeing remnants of it.

[Taco]

Very cool!

I have been mapping the old logging roads to the west of Baldy North Backbone region. Been on one. Wanna go back and explore em with MTB. You in? Camp at Lupine Camp.

[dima]

There are so many of them!

I want to explore lots of these. Doing more of the PL&P is on my list.