Benchmark Zero

If you go to Lownsdale Square in downtown Portland and look closely around the base of the old Spanish-American War monument, you'll eventually come across the tiny metal disk pictured above. You might have seen disks like it around town before; like the others, this disk is a surveying benchmark. Benchmarks are altitude references, basically adding a vertical dimension to go along with the latitude & longitude info provided by milestones and such.

The benchmark in Lownsdale Square isn't just a random one I bumped into. It reads "Initial Class A Benchmark No. 00", which seems to indicate that it's the fundamental datum that the others in town are measured relative to. Which is actually a bit confusing, since the city's history page about benchmarks mentions a different location, part of a building at the SW corner of Front & Washington. So I'm not sure how to explain the discrepancy here. I'll update this post if I happen to learn the answer.

In any case, the City of Portland has one system of benchmarks, and the city also has benchmarks for various nationwide systems as well. For example, contrast this benchmark with the one at the top of Elk Rock, which was emplaced by the US Coast & Geodetic Survey (now the National Geodetic Survey) rather than the City. For info on what all the markings on the latter disk represent, this forum thread seems to discuss them rather exhaustively. Coincidentally, it seems that Elk Rock tops out at almost exactly 200 feet above the height of benchmark 0 if I'm understanding things correctly. Benchmark 0 is 56.667 feet above sea level, while the one at Elk Rock is 257 feet.

PortlandMaps has a layer that shows both extant and missing benchmarks. This map shows the vicinity of benchmark no. 00, with five more extant ones and two missing ones within a 3 block radius. The Transportation Bureau offers a separate benchmark locator that can search by various criteria, including street name, benchmark number, and section / quarter section identifiers. The City of Lake Oswego's benchmark catalog is online too (with ~350 benchmarks), and info about Clark County's system is here, for readers in the 'burbs who don't want to miss out on all the geeky fun. The City of Portland benchmarks alone surely have to number in the thousands, so making a project out of finding them all seems a bit tedious and unrewarding.

Not everyone is as easily dissuaded as I am. It turns out there's an entire hobby around "benchmarking", which is sort of like geocaching without the caching. Geocaching.com has a page about Benchmark Zero including a comment thread with several exciting photos similar to the one you see here.

This point is curiously close to the putative zero point for the Stark Street Milestones, which is said to be at the Multnomah County Courthouse next door. The benchmark obviously came later though. It's affixed to a memorial for a war that happened decades after the milestones went in. The metal disc that replaced the original Willamette Stone also serves as a benchmark, as it turns out.

As you might imagine (if you've thought about it at all, which I hadn't until now), figuring altitude above sea level is more complex on water than on land, especially when you have both tides and varying river levels to worry about. For some info on how this works in our part of the world, see a paper from NOAA's National Ocean Service: "Vertical Control in a Tidally Influenced Complex River System". FWIW.

The View from Elk Rock

In my Elk Rock Island post last October, I mentioned briefly that the high cliffs across the river were a public park too. I put it on my blog todo list (and yes, I do have such a thing) to go check the place out, and I finally got around to it the other day. So this is the place the city calls the "Peter Kerr Property". Or more precisely, I took these from slightly outside the park, at the intersection of SW Riverside Drive (i.e. Macadam / OR 43 ) and SW Greenwood Rd., down in luxo-ritzy Dunthorpe. The park itself is the extremely steep ivy-choked hillside in the foreground of most of these photos. Elk Rock Island is just across the river, and 200-some feet straight down.

I was actually hoping for a better view than this -- I don't see Mt. Hood anywhere, and there are all these ivy-strangled trees in the way. But hey. It is what it is, and now I can tick this item off my todo list, for whatever that's worth.

Since I've already posted on the topic, I won't get pedantic at length about how this is a Portland city park despite being outside city limits, nor will I go on about the curious fact that Dunthorpe's managed to stay outside city limits all these years. I won't do the latter because I'd hate to anger powerful Dunthorpians (Dunthorpites? Dunthorpoids?), who like low taxes and love staying off the radar. Seriously, you don't want to make them angry. A couple of quick phone calls and they'll have you deleted from the space-time continuum, along with all your ancestors going back to the last ice age, and your little dog too.

Needless to say, I won't explain exactly how I got here. I will mention that buses 35 and 36 stop nearby, I suppose so butlers, cooks, gardeners, nannies, and others who serve the Dunthorpii can get to work without sullying the area with their grubby little non-upscale cars. Not that there's anywhere convenient to park anyway.

The photos on the city's "Peter Kerr Property" page (link above) must be from a different vantage point than mine. The park does continue for a couple of blocks or so north of the intersection, so that must be what's going on. I didn't stay long enough to find out for sure, since I didn't much care for all the traffic whizzing by a couple of feet behind me as I was taking these. I'd meant to take a few infrared photos since I've kind of been on an IR bender lately, but after a few minutes I just went, screw it, I'm out of here. This place could be a nice scenic viewpoint if only there was somewhere to stand and take photos without being mauled by luxury SUVs. Of course, that would attract outsiders to the area, and I guess that's to be avoided. Well, plus I don't see the city putting a lot of resources into improving the place if the local neighbors aren't going to pay any taxes for its upkeep. Oh, well.

The Willamette Stone

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Here are a few pics from the hands-down nerdiest state park in all of Oregon. This is Willamette Stone State Park (ok, "State Heritage Site") [map], a tiny spot up in the West Hills just off Skyline Blvd. I've mentioned the now-absent stone and its history before, in an earlier post about Milestone P2, and now here it is in the flesh. Updated: I've since tracked down all the remaining Stark St. Milestones, plus a couple of others around town. You can read the whole set of posts here, if you're interested.

Anyway, isn't this exciting? The disk shown above (where the stone used to be) is the "initial point" for the land survey system covering Oregon and Washington. I'm no expert about land surveying, but apparently this spot is quite important. Or at least it was at one time, back in the pre-GPS era.

A few Stone-related resources on the Interwebs:

• The Wikipedia article tries to explain it all in a halfway-accessible way. I happily admit to being a hardcore nerd, and a bit of a history dweeb too, and even my eyes started to glaze over. I think it was around the time it got to the phrase "Donation Land Claim Act of 1850". Although I'm sure that was a worthy and necessary piece of legislation, probably.
• Mr. Klein of ZehnKatzen Times fame has a better piece about the place here, and a bit more here. He explains all the gory details of the land survey system, so that I don't have to. (Thanks!)
• Another good history here, courtesy of the End of the Oregon Trail center down in Oregon City.
• Bill McDonald (of the late, lamented Portland Freelancer) wrote an amusing 2002 Trib story about the stone as well.

The park's always kind of puzzled me, ever since the last time I visited. (I was in a group of confused and bored Cub Scouts, and the "real" stone was still there, way back when, not that I'm old or anything.) It's quite an obscure thing to create a park around, given all the places and events that go uncommemorated here, and you have to wonder why they went to the trouble. It's possible the state kept it around for reference (again, in the pre-GPS era), not just for historical curiosity, since we aren't the only state to do this. (Yes, it's time to take a deep breath, kids, it's "Dig a little deeper" time again...)

There's Meridian-Baseline State Park in Michigan.

Arkansas has Louisiana Purchase State Park, which was once the "initial point" for the whole Louisiana Purchase, hence the name. That would seem to be a bigger deal than our little park here, but the Arkansas park seems to be just as obscure, plus it's in the middle of a gator-infested swamp.

California's Mt. Diablo State Park has a marker, although it may or may not be correct, I gather.

Illinois has a roadside historical marker.

Idaho's got a marker too, rather more dramatic than ours, and like ours, it's had vandalism issues. I suppose if anarchy and chaos is your thing, a marker that claims to lay out the world in an invisible grid system is not going to be much to your liking. I'm probably reading too much into that. I know I've said this before, but the world would be vastly more interesting if all the vandalism was committed on serious aesthetic or ideological grounds, rather than the "Dude, like, I was, like, here" we see in real life. Sigh...

Utah's is at the SE corner of Temple Square. Gee, nice church-state separation there, guys.

There's a list of initial points nationwide and a map of the territory they cover, plus a bit of background on the Public Land Survey system.

Another list of meridians and baselines here, also including "guide meridians").

Naturally there's an exhaustive reference book about all 37 (or 38?) such points around the country, and the author tracked down and visited all of them. So yes, it's been done already. Feel free to load up the RV and hit the road, though, if you're so inclined.

More info about some of these places here.

There's not much to the park besides the marker. There's a wide spot in the road for parking, and a sign that tries valiantly to explain what the park is all about. A short well-maintained trail heads downhill through the forest to the stone, but doesn't connect with the rest of the trail system in the West Hills. To the west are a couple of huge broadcast towers (Channel 8, among other things), to the east is as-yet-unused cemetery land, and to the south-southwest there's a gated condo community. In the aerial photo on their home page, the park's the forested area in the upper right. You can't get to the park directly from The Quintet, though. There was a time when developers and prospective homebuyers would be thrilled about a connection with the local park and trail system, but that time has long since passed. I suppose it would defeat the point of making the community gated; the evildoers could skulk in through the park and wreak havoc or cause mayhem or something, possibly. Or at least that's what everyone's terrified of, and fear sells.

One fun thing about the park is that it's right next to a couple of gigantic broadcast towers, so that you're strolling along through the forest, and suddenly through the trees you see an enormous orange and white structure stretching into the clouds. It's not something you see every day. Unless you live on Skyline, I guess, which I certainly can't afford to do. Seems there was a bit of a land use battle over the towers -- one was built in 1998 to replace the older one, and they ended up keeping both, and the state wasn't happy about it. If you look at the property details on PortlandMaps, you can see just how tiny the park is. It looks like it's barely wider than the trail as you get down to where the stone is. In this view you can tell pretty much exactly where the stone is: Note the property boundaries (and a road) that run right along the baseline and meridian lines.