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  • Writer's pictureDale Hill

Yuha Desert SMASH

Recovery Date: October 16, 2021 Total Marks Recovered: 42

Yee-Ha Yuha!

Ready to spend the day looking for a LONG list of survey markers!

Welcome to the Yuha Desert, sign located on SR 98

Finding Inspiration

An excellent resource for short hikes & survey marks in the Anza-Borrego Desert State Park

People often ask me how I decide what survey marks to look for, and quite honestly, the inspiration comes from multiple directions. Initially, finding survey marks was a secondary outcome of completing a hike or summiting a peak for a Hiking Challenge; however, as my hobby evolved, I planned Survey MArk Scavenger Hunts (SMASHs) around a single marker or a specific geographical area.

An excellent resource is Robin Halford's "Hiking in Anza-Borrego Desert Volume 3: Over 205 Half-Day Hikes to Survey Marks,"

While photographing a survey mark for social proof that I had completed a hike for the San Diego 100 Peak Challenge, a nearby hiker asked what I was doing. After explaining the nature of the Challenge and my new interest in survey marks, he suggested I check out Robin's book. As we talked, he told me he had illustrated the maps for the book! Shortly after that hike, I ordered all three volumes of the "Half-Day" Hikes in the Anza-Borrego Desert to add to my growing hiking library.

Area 25 - Yuha Desert: Mountain + 13 Marks (p. 194)

I was thumbing through the book when I came upon Map 37 (p.192), which corresponded to Area 25, The Yuha Desert. The 6.4-mile loop (more like a big rectangle) promised 14 survey marks with easy parking just off the Evan Hewes Highway. This loop was the focus of today's trip, so my first step was to plot each potential mark on my map. Next, I decided the route I would drive to reach the trailhead and began researching survey marks I would likely pass on my way there. Finally, I took a big-picture look at the area and selected a variety of survey marks that would make good tertiary targets if time permits; I had a list of more than 60 survey marks to look for!

Establishing waypoints for potential survey mark recoveries.

Kumeyaay Highway (Interstate 8)

Many survey marks have been set near Interstate 8, mostly along the original route. The challenge is finding a safe place to pull off the road to look for them. I've created waypoints for many on the off chance that I can stop and look for them. The first mark on my list was on In-Ko-Pah Park Road, the access road that leads to the Desert View Tower.

A lot of the Bench Marks are registered in the National Geodetic Survey (NGS) database and are also identified on topographical maps with an "X" symbol, the initials "BM," and the elevation of the mark. Generally, the location on the topographical map is very close to the actual location of the mark; having a topographical map layer open in my GAIA GPS App is often all I need to locate one of these marks. When a mark is in the database, its coordinates are provided on the datasheet, and the coordinates' accuracy may vary based on how they were determined. For more information about survey marks in general, you can check out this NGS Survey Mark FAQ.

V 612 (PID: DC1043)

While not a survey mark, the Tower and the accompanying park are Historical Landmarks. Unfortunately, I arrived too early to visit the tower; and when I stopped on my way home, I arrived a few minutes before it closed, but I got a few pictures. 😊 BTW, there is another tourist attraction on the short access road to the Desert Tower: Coyote's Flying Saucer Retrieval and Repair Service. At first, I thought it was just a bunch of junk on the side of the road, but apparently, it is a legit attraction!

CO OF IMP GPS 0001 (PID: AE9209)

I pulled the location of this mark from the NGS Data Explorer and was happy to see a turn-out and space to park one or two vehicles just beyond the rock outcrop where the mark is located. Update: I parked in the same location when I returned in November 2022 to recover the DEVIL, INKO, and GORGE survey marks.

SR 98 "Yuha Cutoff"

The first exit from Interstate 8 (or 'the 8') upon hitting the desert floor is California SR 98 to Calexico; I had plotted several waypoints on the 98 and decided to explore this area before continuing to my primary destination on West Evan Hewes Highway (Imperial County Route S 80) about 8 miles further East.

Nicknamed the Yuha Cutoff, SR 98 is 56.85 miles long from the point it leaves I-8 and rejoins it east of Holtville. There are a LOT of survey marks on this road, but I only traveled 4 miles before turning back around to head for Ocotillo and my primary objective. Naturally, I made a mental note to return and thoroughly search SR 98 later.

My first stop was at the Yuha Desert sign for a selfie and to look for a Public Land Survey System (PLSS) Corner marker about 50 yards from the sign. Not only did I recover the section corner I was looking for, NE Corner Section 1, Township 17S, Range 9E, SBBM, a closing corner, but I also had two surprise recoveries; the first, IMP 12A 26A was 30 feet from the sign, marked with a traditional CalTrans witness paddle.

A Closing Corner is established where a survey line intersects a previously fixed boundary at a point between corners. Usually, corners follow a neat grid; however, in the etched detail on the disc, the Section 1 corner for Township 17 meets the southern boundary of Township 16, somewhere in the middle of Section 35.

The second surprise recovery was another PLSS Corner, SE Corner Lot 16 Tract 69 (Angle Point 4) of Section 35, Township 16S, Range 9E, SBBM. This was much more fun to research, taking me back to the original surveys conducted between 1854 and 1880! Lot 16 was surveyed in January 1921, as noted by the date stamped on the disc. This survey mark was like a history lesson all by itself 😉

Continuing East, I found two named stations, SITKA (PID: DC2142) and MIRAGE (PID: DB1813); both stations were California Department of Transportation discs established in 1977. I was fortunate to find all four discs for SITKA: the Station, two Reference Marks, and the Azimuth Mark. As you can see from the photo, the MIRAGE station has seen better days; when this was originally established, the top of the concrete monument would have only been a couple of inches above the ground. I could not locate Reference Mark 2 and the Azimuth; they may have been buried or destroyed.

The final three survey marks I recovered on this stretch of S 98 were PLSS Corner markers that I identified using the PLSS grid overlay on my GAIA GPS App, cross-referenced with the USGS Topographical map. Not every section corner is marked with a disc or stamped pipe cap; however, if the topographical map has a symbol denoting a corner, there's a good chance they'll be a formal marker.

Imperial County Route S 80 - West Evan Hewes Highway

Today's next collection of recoveries was located on an 8-mile stretch of Imperial County Route S 80 (West Evan Hewes Highway) between Ocotillo and the Mountain + 13 Marks Hike trailhead.

This set has a little bit of everything: traditional Bench Marks, a Triangulation Station, a Reference Mark, a Station Reset, and a PLSS Corner Mark.

Mountain + 13 Marks Hike

Date: October 16, 2021

Distance: 7.15 miles

Total Elapsed Time: 3h 49m

Total Moving Time: 3h 15m

Highest Elevation: 240 feet

Elevation Gain: 124 feet

Trailhead: West Evan Hewes Road

I parked on the north side of the road and made a quick trip across the road to recover Bench Mark X 90 (PID: DB0808); like many survey markers out here on the flats, it was easy to spot the concrete monument and witness sign from the road. Crossing back over the road, I started recording my track in my GAIA GPS App and headed north toward the first mark on my list. The map and legend in the guidebook use a simple alpha-numeric numbering system, where the first position is a letter: C - Corner, L - Line, M - Mark, followed by three digits. B - Bench Marks are identified by their name (no numbers).

In this context, the "Line" indicates a place on the section boundary that is not a primary Section Corner; in the PLSS, these are called Quarter Sections or Quarter-quarter Sections and are identified by their location within the section. I've listed all the marks on this hike using the guidebook's designation and provided the PLSS description for each. These marks are all within Township 16 South, Range 10 East, San Bernardino Base Meridian (016S 010E, SBBM).















** These survey marks were not found.


It's not uncommon to find multiple survey markers identifying the same location, 🙄 set by another surveyor who calculated the location differently. I found this 'tack and tag' in a 1" iron pipe, stamped with the surveyor's license number, 6310 (McHugh, Kevin Douglas, Jr.) nearby NE CORNER NESE ¼ SECTION 11, TOWNSHIP 16S, RANGE 10E, SBBM. 🤷🏻‍♂️


The guidebook lists the Bench Mark named MOUNTAIN at coordinates 32º 47.266'N, 115º 54.030'W, about a 0.5-mile walk from the parking area, indicating that the pedestal is broken. There is a broken pedestal (concrete monument) at that location; however, that base belongs to a different survey mark. I found USACE PP3 AT6 (PID: N/A) approximately 12 feet SW of the broken base (see image four below).

USACE PP3 AT6 (PID: N/A) is considered destroyed because it is no longer in its original position and cannot be used as a valid control point. I could not find either survey mark in the NGS database. Because I could not find any solid evidence of the mark MOUNTAIN, it would be considered: Not Found When reporting recoveries, the NGS has four categories used to describe the condition of the survey mark:

  • Good: No evidence of tampering.

  • Poor: Damage is present, but the mark could still be used as a control point

  • Not Found: Existence is doubtful

  • Destroyed: There is irrefutable evidence of destruction.

It's easy to assume that a mark is destroyed because you can't find it, but I've found marks I was previously unable to locate, usually because the mark was buried and I just had to dig for it. Also, the coordinates listed are not always 100 percent accurate; I have found marks as much as 250 yards off from the stated coordinates; this is why the narrative "to reach" directions in the datasheet are very important. They explain how to reach the mark, where it is set (concrete monument, rock outcrop, bridge abutment, etc.), if a witness post is nearby, etc.

The results of my hike and survey mark hunting are represented on the GAIA GPS base map with the PLSS overlay

Back on the Road

W 90 (PID: DB0807) and T 1246 (PID: DB0805)

It was close to 4:00 p.m. when I wrapped up and was back at the truck; I made two more recoveries on S 80 before I decided to turn around and head home.

MESH (PID: DC0200)

On the drive home, I stopped to get fuel and something to eat at the Golden Acorn Casino and Travel Center. While waiting for my dinner, I reviewed the recoveries I'd made and recentered my GAIA GPS to my current location to see any marks nearby. To my surprise, one was very close to the off-ramp for the 8! On my way out, I stopped and made these final two recoveries for the day!

Overall, this was an awesome day; I logged over 10 miles in the desert, looked for survey marks all day, and came home with 42 recoveries! Not a bad day at all! 😉

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