top of page
  • Writer's pictureDale Hill

Sea Level to Soledad SMASH!

Updated: Jul 7, 2021

Total Marks Recovered: 38

The number of Different Types of Marks: 14

Disc Marks: 30 (7 different types)

Non-Disc Marks: 8 (7 different types)

Steps: 12,739 Miles Walked: 4.6 miles

Total Elapsed Time: 8h 55m (from the first photo to the last photo)

Moving Time: 2h 52m

Parking Fees: $10.50 Scooter Fees: $7.67

Survey MArk Scavenger Hunt!

Today's SMASH (new acronym alert!) took me all over San Diego, literally from sea level to the top of Mount Soledad and a lot of cool places in between. "Snap-to-snap" I was out for about 9 hours, photographing my first recovery in La Mesa at 0848 and wrapping up with the last photo on top of Mount Soledad at 1743. I planned my day with much more driving than hiking out of deference to my knee injury, overall that plan worked out really well.

Just a heads up, this is post is going to be longer than normal, yes there are lots of pictures, but there is also a story behind the marks, I hope you hang out and enjoy the ride as I take you through my day.

This map shows the order of my recoveries, the green stars are major stops in the order I made them and the number of recoveries at each location is noted in the blue circles. It was a gorgeous day out and for the most part, each location gave me an opportunity to walk around a bit and enjoy a good variety of what San Diego County has to offer.

Recap of Today's SMASH: Green stars are the order of my stops; blue circles are the number of marks found

I spent a lot more time planning this day because I knew I wanted to keep my walking down to a minimum. I always use the National Geodetic Survey (NGS) Data Explorer as my first tool to identify potential marks for recovery. I can zoom out on the map and get a good sense of the density of survey marks in a particular area, from there I can call up the datasheets to look at the recovery history and see which ones have a strong likelihood of still being there. I'll also scan the target area on my Topo map to see if there are potentially benchmarks listed on the map that are not in the NGS database. I added a third tool to my research list for this trip, the Waymarking website. I was able to search their extensive database of recorded waymarks, specifically narrowing my search to benchmarks found in California. I scanned their database for marks that were tagged as being found in or near San Diego. This was a time-consuming process, but it netted a couple of recoveries that I may not have otherwise found. The flip side of that is the database is somewhat dated, I had jotted down several marks to look for that were originally recovered over 10 years ago in good condition, but were no longer there.

La Mesa

My first stop as I headed toward downtown San Diego was a quick pass through La Mesa.

This commemorative survey mark was a very cool find that I saw in the Waymarking database. It's mounted on the sidewalk right by the La Mesa Depot Train Museum at the corner of Spring Street and Nebo Drive. The disc celebrated the Centennial of the City of La Mesa, the "Jewel of the Hills" in 2012. Up until this point, the extent of my "custom or commemorative" recoveries have been the REI and Mission Trails discs.

Balboa Park

This was too funny. When I was scanning the NGS Data Explorer Map, I noticed a single survey mark in Balboa Park, when I zoomed in on the map, I saw a VERY familiar sight. Designated officially in the NGS database as "Balboa Park Highest Tower", the California Tower and the San Diego Museum of Man had been the backdrop for hundreds of Pedicab passenger photos I took over the 11 years I operated my pedicab business in Balboa Park.

Pops' Pedicabs in the California Quadrangle c. 2013

It brought back great memories to wander through the Park again, I really hadn't been back since I had closed my business in 2015. I spent almost every weekend in the park providing pedicab shuttle services throughout the park, giving narrated historical tours, and handling transportation for special events such as weddings and festivals. Originally built for the 1915 Panama-California Exposition the complex includes three primary structures, the California Building, the California Tower (this mark), and the California Quadrangle. The main exhibit during the first Exposition was "The Story of Man through the Ages" which was primarily an archeological and anthropologic exhibit. During the 1935-36 California-Pacific Exposition, the building was briefly renamed the "Palace of Science" in keeping with the naming conventions for that Exposition. The building was renamed "The Museum of Man" in 1942 to more closely align with its focus on Anthropology ("San Diego" was added to the name in 1978). In 2020 it was renamed "Museum of Us" in a move to be perceived as more inclusive.

The Museum incorporates three other nearby buildings (all originals from 1915), the first Balboa Park Administration Building (next door), Evernha Hall, and Saint Francis Chapel both across the street on the other side of the quadrangle. The California Tower houses a carillon that chimes on the quarter-hour and can be heard throughout the Park. Access to the tower had been restricted for over 80 years but was re-opened in 2015 in time for the Centennial Celebration of the Panama-California Exposition.

Thanks again to the Waymarking website, I learned that there was a benchmark located at the West end of the Cabrillo Bridge, not too far from the dog park. This was actually my first recovery in the Park today as I parked on Juniper Street near 6th Avenue and walked into the Park from there. As I approached El Prado at the end of the bridge, I started searching on the concrete walls for the survey mark (H 18), it was a pretty easy find since I knew it was mounted on a low wall.

I continued through the Park, grabbed my pictures of the California Tower then headed toward the San Diego Natural History Museum. My Topo map indicated a benchmark (H 19 RESET) was located right in front of the Natural History Museum. Again, I was somewhat dumbfounded because I had posed many pedicab passenger photos directly over this mark and I can't ever remember noticing it! This morning there was a "Mommy & Me Stroller" group doing a fitness workout on the steps of the SDNHM so I jumped in quickly to prep the mark, take my pictures, and get out of their way.

BIRD Electronic Scooter

It had been a nice walk through the Park but I wasn't looking forward to the slow walk back to the truck as I still had a lot of stops on my agenda. I spied an electric rental scooter nearby and decided to check it out. I'd never used one of these before but it was the perfect solution to get back to the truck quickly and minimize the strain on my knee. So for about $8, I took this little scooter ride back across the Park, it was a BLAST! 😂🛴

San Diego County Administration Building

Sometimes you need to have the SUPER EASY recovery! 🤣 When I was checking out the NGS Map, I noticed this large grouping of marks downtown. Zooming in on the map, I noticed they were all on the same building! There were originally 16 marks mounted vertically on the building, 4 spaced out on each side (N, S, E, and W). These are all true benchmarks, meaning their purpose is to measure elevation, and were numbered in the series H 1 to H 16. In researching the datasheets, mark H 4 was noted as destroyed when they installed an ADA compliant access ramp on the southern side of the building.

The San Diego County Administration Building sits between North Harbor Drive and Pacific Highway on a plot of land about 5 city blocks long, the area surrounding the building is designated as the Waterfront Park. In addition to the County Admin building, there's lots of lawn space where people can picnic, plenty of fountains and water features that kids can play in, and a full playground. Being a nice Saturday morning, it was a busy spot, but I was lucky to snag a non-metered parking space directly in front of the building just off Harbor Drive.

Generally speaking, all of these marks were pretty easy to find. I knew they were mounted vertically and their locations on the building were fairly consistent. The challenges in recovering all of the marks were that some were partially covered in paint while others were mounted in the wall above recessed walkways. Even though those marks were at eye level when I was standing opposite them, there were at least 15-feet above the walkway below. I had to take my close-up pictures resting my iPhone on the iron fence rail and use my 10X Zoom to get the detail of the mark, of course, applying chalk on these marks was out of the question because I couldn't physically reach them.

As I worked my way around the northern side of the building, two security guards from a private security agency approached me and told me that I couldn't be near the building and that I'd have to leave. However, once I explained what I was doing (which included a 60-second "elevator pitch" on what survey marks are and how they are used), they allowed me to continue. I was respectful, promised to stay on the dirt pathways, and assured them I would not step on any plants while I was continuing my recoveries. Had I seen them before I started, I would have approached them first and let them know what I was doing.

Here are all 15 marks that I recovered at the County Administration Building, the first photo is the close-up followed by an "eye-level" view of the mark. I'll break them up into a couple of different galleries

H 1 to H 3 and H 5 to H 8.

H 9 (PID: DC0900)

H 9 was an interesting one as it was just above the level of an ADA Access Ramp and they had installed conduit right over the top of the mark! Probably not the most effective position to use it as a surveying point 🙄 I did think it was kind of a cool coincidence that mark number "9" had a permanent ID of DC0900.

The final Gallery: H 10 to H 16

As you can see, some are easier to get to than others. the ones that were near the main entrance doors were pretty easy to access and I suppose I could have chalked them up to call out the stamping and make them more readable. 🤷🏻‍♂️

Why So Many?

I've had a few people ask why there are so many survey marks on this one building and that's a real good question. It seemed that 16 marks might be overkill, but without seeing the original survey or the accompanying field notes, I simply had no idea.

I posed the question to a group of Surveyors that I follow on FB and a few of them agreed that they were probably used to monitor settlement of the building, not uncommon if there was major construction going on nearby (such as interstates, subways, etc.) I went back to research a little more about the building and found out that it was completed in 1938, so these marks were all placed when the building was brand new, very likely before any other major construction was going on.

Further research indicated the site of the building was on previously dredged tidelands and when the building was originally proposed in 1926, there was a great deal of concern about building on the tidelands and the potential impact of earthquakes. When construction finally began (post-Depression), the engineers used cutting-edge methods (at the time) to stabilize the building. Knowing that there was concern about the stability of the building and the stabilization methods used were new and untested, it makes perfect sense that they would install so many survey marks around the building so they could monitor if the building settled, and by how much. Seriously, I learn something new every day! 😊

The Embarcadero

There are two NOAA Tidal Stations in San Diego County, La Jolla Station ID: 941 0230, and San Diego Bay, Station ID: 941 0170. This past February I spent a morning wandering around the Scripps Institution of Oceanography campus looking for Tidal Stations and Benchmarks (see my post Buried Treasure and More for more about that trip). On that excursion, I found my first Tidal Benchmarks which were also the first marks issued by the National Ocean Survey that I'd recovered. Today I had a handful of survey marks from the San Diego Bay Station on my radar. I had looked for a couple of these tidal marks in and around the Embarcadero last December while I was downtown running other errands. However, I wasn't really prepared to hunt them down and the couple that I had coordinates for, were either in current construction zones or were paved over by parking lots.

Bolstered by evidence of successful (albeit, old) recoveries on the Waymarking site, I drove over to the Midway Museum, paid for parking on the Broadway Pier, and set out searching. None of the five marks I located today were listed in the NGS database and I hadn't thought to print out the Benchmark directory for the San Diego Bay Station from the NOAA website, so I was really counting on the information from the Waymarking site to get me close.

Tidal Benchmarks and Station Discs

I located 4 of the 5 Tidal survey marks on my list, a couple were mounted in the concrete bulkhead on the edge of the pier, and the other two were located in the concrete near storm drains. The ones near the storm drains were a little trickier to find because the concrete around the drain was covered with decorative wood chips and mulch.

You may notice that two of the discs are stamped National Ocean Survey and the other two are stamped National Ocean Service, it's the same organization. Here's a quick recap of the different names through the years. They probably would have used up all the discs prestamped with National Ocean Survey before using the one stamped National Ocean Service, even if the date of the mark was after the official name change.

1807 - Survey of the Coast (Est. by Thomas Jefferson) 1836 - Coast Survey 1878 - US Coast and Geodetic Survey (USC&GS) 1899 - Coast and Geodetic Survey 1979 - National Ocean Survey 1985 - National Ocean Service 1970 - National Geodetic Survey (NGS) * * The NGS is actually a functional unit within NOAA’s National Ocean Service

San Diego Unified Port District - GPS Control

This is the second Port District GPS Control disc that I have found downtown. I was prepping this mark with chalk to photograph it and I noticed a few people that were watching me intently. Once I took this close-up shot and stood to get my "eye-level" picture, one young couple had questions about what I was doing.

Always happy to share, I explained the purpose behind GPS Control Points and survey marks in general. I shared some pictures of the other marks I just found over by the USS Midway and explained a little about Tidal Benchmarks as well. They thanked me for the info and continued on along the boardwalk while I headed off to continue looking for the other marks...totally forgetting to take my eye-level photo for this mark! 😂

Hotel Del Coronado

Next, it was a drive across the Coronado Bay Bridge to recover two more "non-disc" survey marks. Part of the exciting thing about today's SMASH was that I found a total of seven marks that were NOT the typical brass disc marker. Both of these marks popped up on the NGS Data Explorer and as I zoomed in on them I saw they were both parts of the Hotel Del Coronado. We've stayed at the "Del" a few times in the past and I was sure that I had taken plenty of pictures of the hotel and surrounding area, so I figured I could use one of those shots as my "recovery" photo in my database. Of course, all my pictures were of the inside of the hotel, the beach, or outside nighttime pictures with the building lit up for Christmas, so I went back today to make a proper recovery.

The main tower with the American Flag flying is actually considered a "Lookout Tower" and the smokestack is a "Chimney"... my first chimney recovery!

The Hotel Del Coronado is such an awesome place to visit with incredible history, I highly recommend it as a fun day trip or vacation destination. Both times we stayed there it was during the Christmas Season (our office Christmas Party was there) and the decorations, atmosphere, and dining were all simply amazing.

Chiseled Crosses

I posted these pictures on my IG account as a couple of Survey Marks that didn't make it into my database. These were located on the sidewalk along Orange Avenue in Coronado spaced about 200-feet apart, I just happened to look down and notice the faded paint around the chiseled cross in the sidewalk. They are considered crosses, even though I always orient my camera to make them look like "X"s 🙄 Marks such as these, and nails that are driven into the concrete or pavement, are literally ALL. OVER. THE. PLACE. these are like the working survey marks for a variety of survey types that include road surveys, right of way, and property line surveys. Once you know they are there, you'll be amazed at how many you notice while you're out walking around.

Harbor Island

When looking at the NGS Data Explorer map of San Diego, marks that are located on Islands and in funky places tend to stand out. When I saw the mark listed as the Harbor Island Light, I was excited for a chance to recover another new type of mark.

This particular mark is listed by the NGS as a "Spire" and according to the datasheet, it is part of a small operational lighthouse. This light sits atop the Tom Hams Lighthouse Restaurant at the West end of Harbor Island and can be seen from the parking lot as well as from the bay.

After I recovered this one, I headed to the East end of the Island to recovery my next mark, which just so happened to be close to one of my favorite restaurants in San Diego, the C Level Lounge. I was tempted to stop in for a late lunch, but I still had a full day ahead of me. I parked and walked down the sidewalk toward the HAY station, located near the second turnout area on Harbor Island Drive.

Well before I reached the area where the mark was supposed to be, I came across a survey mark epoxied to the sidewalk, it was a shiny brass disc about 1 ¾ inch across stamped "S.S.1. A". It was in really good shape but didn't have any markings to indicate who or what agency set it there. Still, it was a bonus recovery, so I snapped my photos and continued down the sidewalk. When I got home, I searched the SD County Surveyor online database but couldn't find any reference to this particular mark.

As I approached the turn-out area, it was pretty easy to see my next mark, it was mounted on the sidewalk in the middle of a faded white circle with a larger blue circle painted around it, kind of hard to miss! I was expecting to find the HAY 1964 Station, also a California Division of Highways 2" disc, but this HAY 1968 RESET disc was all that I found. The reference mark for the original station ended up being in the middle of a parking lot, so it's safe to say that it was either buried or destroyed. The RESET disc did not have a permanent ID assigned and there was no mention of any reference marks for it.

Point Loma

Today seemed to be a day to find marks that had been painted over! PLS 3 made my list of recoveries because it was only a couple of blocks from another potential recovery, the San Diego Yacht Club Flag Pole. As it turned out, I passed on the Flag Pole mark as I imagined had to be a member, or be a egistered guest of a member, to access the grounds. This mark was almost completely covered with red paint from when the curb was painted so I grabbed a razor blade from my truck and carefully scraped enough of the paint off so I could read the designation and year. I probably should have gotten that last little bit that covered "TRANSPORTATION" but this was a tedious job. There are a total of seven marks in the PLS series that have been set in Point Loma (PLS 1 through PLS 7), I've put it on my list to recover the rest of them the next time I am out that way.

Station: MID (DC1689)

This was a great find along my way to the Rosecrans National Cemetary, I'd seen the location on both the NGS Data Explorer and my Topo map, but I wasn't sure if it was accessible (many marks on Point Loma are actually on U.S. Navy property or within the boundaries of the National Park)

The original mark for MID was a 1" iron pipe driven into the ground, in 1933 the current U.S. Coast and Geological Survey discs were placed on the exact spot of the original pipe. The surface mark seen here is mounted on a concrete slab about 24" square, there is an identical underground mark set in a concreted block directly beneath it. There are supposedly a couple of reference marks nearby, however, since I had it listed as a "Maybe", I didn't dig into the exact location of those reference marks. I'll look for those next time.

I did think I had found the location of one reference mark (see the third picture) it sure seemed like it should have been a reference mark, but when I got home and checked its location, it didn't agree with the description, distance, and directions for any of the listed reference marks.

This mark is located very close to an underground bunker that was part of the Coastal Defense system established to protect the bay and coast during WW I and WW II. I will plan a full-day trip to Cabrillo National Monument to walk all the grounds and dive into the military history of the area as well as to look for all the survey marks within the Park boundaries. Last year I came out and hiked the Bayside trail as part of the SD 100 Peaks Challenge, but I didn't have a lot of time to explore the rest of the Park.

Bonus Survey Point Recovery

While I was looking around the general area of the MID station, I noticed this survey point set in a concrete slab that was apparently the base for some type of artillery gun. I couldn't find any reference to it in the SD County Surveyor's online database of surveys of the region. I probably would have ignored it if it hadn't been stamped, perhaps the more I research and explore the area, I'll come across more information about it.🤷🏻‍♂️

The USS Bennigton Monument (DC1663)

This was another "first" recovery for me, the type is "Monument" and it was curious to me that a memorial monument in the Rosecrans National Cemetary was designated as a survey mark, but it IS a readily visible and permanent structure.

This is a 60' dark granite monument with a pyramidal top. It is a monument to the men of the U.S. Navy gunboat USS Bennington that died when the boiler exploded on July 21, 1905, while the boat was in San Diego Bay. Sixty-six people died and 46 others were burned. At that time, it was the worst peacetime disaster for the U.S. Navy.

Mission Bay

The last part of my pre-trip planning was to see if there were any survey marks listed on the GPS on Bench Marks priority map near where I would be throughout the day. To my surprise, there were only two! I added the Vertical Control Mark, station E 1415, to my list for today and made a note that SDGPS 23 would have to wait until I returned to Cabrillo National Monument since it was inside the Park. E 1415 brings my GPS on Bench Marks submissions to 18. I think I need to plan a SMASH trip just to find GPSonBM marks!

DC1434: E 1415 (10 km, Priority A-1 Observation)

Soledad Mountain

Phew! The last stop of my day (at least for survey mark hunting) was Soledad Mountain. There were lots of marks in and around the mountain however, several were on private property, behind locked gates.

UPDATE: July 7, 2021. I just discovered that the Cross at the top of Mount Soledad is a survey mark in its own right! The present structure was erected in 1954; it is the third Christian cross in that location, the first having been put up in 1913. Architect Donald Campbell designed the present cross in prestressed concrete. It is 29 feet (8.8 m) tall (43 feet tall including the base) with a 12-foot (3.7 m) arm spread. It is the centerpiece of the Mt. Soledad National Veterans Memorial. The cross was the center of legal battles surrounding the First Amendment Rights and the separation of Church and State for more than two decades. The non-profit organization, Mount Soledad Memorial Association, purchased the land under the cross, effectively ending the Constitutional battle.


Azimuth Marks are usually difficult to find and I have only recovered three survey marks that are described as type "DZ - Azimuth Mark" which means the disc is prestamped as an Azimuth and issued by the NGS or one of its predecessor agencies. I have found an Azimuth disc issued by the California Division of Highways, but in the NGS system, that is classified as a "DD - Survey Disc (Other Agency)".

The hardest part of recovering this one was climbing the stairs with a bum knee, at the end of a long day! I've been to the top of Mount Soledad many times before, but I've never explored the monument. All of my previous trips were on my bike 🚴 as part of a challenging climb up from La Jolla Shores, it was kind of nice to drive the truck to the top this time! 🤣

It was nice to end the day with two Easy-Peasy recoveries, two Radio/Television Masts located just below the top of the mountain. The KOGO mast now broadcasts KGTV and is an ABC Affiliate owned by Scripps Broadcasting, KFMB is a CBS Affiliate and the mast is owned by Tenga Inc.

End-of-Day Wrap-Up

This was a fun day. Usually, my weekends are spent out on the trails hiking, however with the current status of my knee, extended walking/hiking is on the back burner. I expect I'll be planning a few more SMASH adventures (I love my new acronym!😂) like this while I recover and build the strength/stability I need to resume hiking, so stay tuned. If you stuck with me and read this entire post, THANK YOU! I hope you found it interesting and maybe even a little educational. 😊

Recent Posts

See All


bottom of page