G 4: Firebreak Lost and Found
Date: May 7, 2021
Distance: 1.95 miles
Total Elapsed Time: 1h 45m
Total Moving Time: 1h 4m
Summit Elevation: 7,231 feet
Elevation Gain: 594 feet
Trailhead: PCT Grassy Hollow, Vincent Gap
Previous Ascents: N/A
Peakbagger Peaks - 1, Baden-Powell Bench Mark G 4 (Prov)
Survey Marks - 2
PCT - Grassy Hollow Trail
A key part of my pre-hike planning routine is to search the National Geodetic Survey (NGS) Data Explorer system for potential survey mark recoveries, not only on my intended route and summit but on nearby peaks as well.
Yesterday, after making notes and plotting distances for the marks at the summit of Mt. Baden-Powell, I saw that there was a Triangulation Station labeled "Mt. Baden-Powell G 4" basically right across the Angeles Crest Highway from Baden-Powell. To make things easier, it was less than a mile from the Vincent Gap parking lot right along the Southbound (SOBO) Pacific Crest Trail (PCT) also called the Grassy Hollow Trail.
I thought it was somewhat ironic that both survey marks I recovered this morning ON TOP of Mt. Baden-Powell were labeled "North Baldy" and this station on a small ridge, across the street and along the PCT route was actually labeled "Mt. Baden-Powell". I HAD to go find them!
We had gotten back down to the parking lot at 1300, I dropped my pack off at the truck, grabbed a cold drink, and set out across the street with one trekking pole and my recon bag. I did clip my SPOT X two-way messenger onto my recon bag as part of my standard safety protocol. My SPOT X usually lives on the shoulder strap of my pack, but I make it a point to carry it on my person whenever I drop my pack to explore a terrain feature or auxiliary trail, you just never know if (or when) things are going to go sideways, so it's best to be prepared.
I was off to a great start, about 20 twenty feet down the trail on the left, I walked right by a rock with a survey mark mounted on top! You can see the edge of the rock slightly sticking out from the brush in the picture above. This one was a bonus, it wasn't listed in the NGS database, so I mentally dubbed it a "Walk-By" Recovery 🤣 You can compare the photo below to the one above and see that this mark is seriously right at the start of the trail. If you look closely in the one below, you can also see where someone tried to pry it off the rock. 🙄Really people?!
The cool thing about this mark is its designation: "R 94", the Station Disc that was set on the Summit of Mt. Baden Powell (which was subsequently considered to be lost/destroyed) was the same style disc designated as "R 93" also set in 1929. Nifty.
On the descent from Baden-Powell, I paused when we were at about the same elevation as the G 4 station and looked across the gap thinking "If I only had a monorail or zipline to get over there!" 😂 Standing at the trailhead looking up, it seemed pretty steep, and while the first little bit of the trail was, it soon started to snake around the hill and become a more moderate climb. Just this small section of trail was very picturesque and it felt like a nice "cool down" hike given the climber earlier this morning.
The G 4 survey marks were located near a turnout area on W. Blue Ridge Road (USFS Road 3N26.2) at the junction where the PCT crosses the road. The trail continues North around Vincent Gap Peak then heads East toward Jackson Flat Campground and Grassy Hollow Visitors Center. All my directions to locate the station and reference marks were based on distances from the centerline of the fire road. When I had looked across the gap earlier, I could see areas that had obviously been cleared as a firebreak, hiking up the trail I went past large swaths of chewed-up vegetation and cut trees, also part of that firebreak. I really didn't pay it much mind until I reached the turnout area, took my bearings, and saw that the firebreak went right through the area where the marks were supposed to be 😳. My heart sank. I could see one witness post (referred to as a guard post in the datasheet) leaning over, another was mangled in a heap of dirt and sticks.
This slideshow starts out with a few pictures of the concrete monument for Reference Mark 2 after I found it, dug it out, and flipped it over. The rest are just shots around the top of this ridge where they cut the firebreak. This firebreak was done sometime during last fall's fire season as I found a trip report where someone recovered the station mark and both reference marks in pristine condition on August 31, 2020.
Mt. Baden-Powel G 4 RM 2
I poked around in the debris and found a couple of big chunks of poured concrete, one was a section about a foot long and was broken off at both ends. The second one (shown here) had the rough end sticking out of the dirt. I brushed off enough dirt to reveal the finished corner of the monument. From there I dug it out and flipped it over to find the station's Reference Mark No. 2. (I wish I'd taken a picture before started clearing the dirt and sticks away to uncover the corner as all but the very end was completely covered!)
The two witness posts were still in the area, one was bent and flattened on the ground in the vicinity of where the station mark should have been, however, there was no evidence of the surface mark. The G 4 station does have an underground mark, which is identical to the surface mark (same kind of disc, mounted in a 12" x 12" concrete monument) but the datasheet said it was set 2.9 feet below the surface. And I figured that was 2.9 feet BEFORE the disruption caused by creating the firebreak. Too, I didn't have a shovel to dig for it.
The other Witness post was just loosely stabbed in a dirt pile, not likely in its original location. Based on the information in the datasheet about the location of the station, and the distances to each reference mark, this mark and what was left of its concrete monument had been pushed significantly away from its original position, not to mention that it had been upended. I spent just under an hour at the site, digging up this mark, and walking the entire area hoping I'd find more concrete chunks or evidence of the other two marks.
Most of the piles created by the bulldozers and other heavy equipment were fairly loose and easy to probe with my trekking pole, but outside of the two significant pieces of poured concrete I'd found right away, I didn't locate any others.