Sunday, March 11, 2007

Survey Says

Went for a drive today, starting before dawn and heading east.

The purpose of the mission was to complete a land survey of one square mile in the high desert.

Specifically, we were finding and marking the four corners of a mapped section, which is one square mile by definition but sometimes isn’t completely square or exactly a mile. Once a section has been surveyed, though, its corners are exactly where they are, no matter what size or shape that makes the section.

For those who are keeping score at home, a section (a square mile) is 640 acres, which means if you cut it up into 16 equal pieces, you’ve got lots of 40 acres. Match one of these lots with a mule, and you’ve got a fine gift for a soldier after the war.

Finding corners to anything in wide open spaces is like finding a needle in a haystack. On paper, you know where it is, but that’s a pretty wide expanse out there, and the road on the map isn’t always exactly where the road is in real life. The marker for the corner is typically measured in inches, and you’re trying to find one of these in a mile. See the marker in the ground next to Bill’s feet above? That’s not a corner marker.

We were also looking for a bunch of little buttons like these, that mark various other positions in the desert. Unfortunately, this wasn’t one of the ones we were looking for. Never did find them. We got by in other ways.

Fortunately, we had electronics on our side.

Lots of other things are marked in the desert, some more carefully than others. This can help you get your bearings, double-check the electronics, make sure you’re in the spot you think you’re in.

The area we were in has fabulous geology, laid bare instead of covered by a bunch of obscurantist biology. Check out how many different colors of rock are in the hills in the background above. Note the moon snagged in the power wires. Later on we saw it break free and float higher in the sky.

The guys behind Bill are excited because they’ve found the corner marker we were looking for. It’s hard to see in this picture, but it’s there. Look for a vertical stake, tiny here, slightly off to their left, sticking up from a bush.

This is what we’re looking for.

Here Bill takes notes and checks his electronics to make sure we’re calibrated perfectly for finding the next point. We expected to find the stake here, from previous descriptions. We were surprised (and pleased) to find a more recent marker from a 2003 survey. Extra points if you can define “cadastral.”

Like all good explorers, we marked our discovery and took pictures with it. From left to right: Bill, Archie, Ed, Carol, and Bill. A dog at Carol’s feet rounded out the survey party; we’re keeping his name private to prevent identity theft.

This was supposed to be the easiest corner to find, because it was supposed to be marked. From here on in, we were going to have to rely on electronics and careful alignment to determine where the other corners were. We were glad to find this one. In the case of the particular section we were surveying, it doesn’t sit exactly square north-south, so it’s not as simple as going due north or due east to find the other corners. You have to do some math and calculate how far off plumb the next corner should be. None of us is a professional surveyor.

Ed goes hunting for the next corner. Pretty much you just squint at the GPS screen and say, “I think it’s here.”

Except—surprise, surprise!—we found a naturally occurring corner marker had grown between some rocks. (Note no stake with this one, so to find it you have to spot the rocks gathered on the ground.)

This certainly boosts your confidence in your ability to find the right spot.

Having found two corners, we marked the second one with our own stake and set out to travel the line between them, marking it at regular intervals. As you can see, the section line travels across a dry lake. The original stake is over on the left, at the near edge of the dry lake. Two intrepid explorers are out on the lake bed, wearing appropriate safety equipment in case the boat sinks. Leading the charge is one of the expedition’s pickup trucks, specially equipped with flotation devices for situations like this.

This close-up may make it easier to spot the details.

Here’s a fresh stake marking a quarter-mile point, with another stake just visible in the background, a quarter-mile away. For those of you who use metric, a quarter-mile is one-quarter of a mile.

Once you know where to look, it’s much easier to spot other people’s markers along the same line. The stake in the foreground is probably from a public utility; the sign keeling over in the midfield is probably something from the Bureau of Land Management warning people not to get stuck in the mud. In the distance, past that, you see the stake that was in the foreground in the previous picture. Somewhere in the picture is another one of our stakes, but I’m not spotting it.

Having found all the easy pickings, we decided to try for the most obscure corner to reach. We drove to the top of a ridge and looked out toward it in the distance. At the bottom of the rise was a dry wash, and it didn’t look like the truck would be able to get across. We elected to walk.

We didn’t know it till we got there, but the spot we were looking for is directly over Bill and Archie’s heads in this picture. It’s about three-quarters of a mile away. You’ll see a diagonal scar across a patch of darker stone—not the stone at the top of the mountain, and not the lighter stone underneath it, but the darker strip under that. At the bottom end of that scar (which is some kind of road) is the point we were seeking.

We actually had a very pleasant walk in the afternoon sun. Bill was carrying a heavy metal stake; Archie is carrying the heavy tool we use to pound the stake into the ground; I was carrying water, binoculars, GPS, camera, etc. We left the stake behind us at the destination point, and drank some of the water. That lightened our loads, so we all took shifts carrying the pounding tool back to the trucks. When I got back to civilization later in the afternoon, I saw a thermometer that read 80 degrees, which sounds about right.

The trucks, incidentally, are just visible in this picture. They’re parked on the ridge behind Bill and Archie, just about exactly between them, right up at the top of the slope. Carol and the dog stayed with the trucks.

We found what we were after. This marker had two stakes next to it already. We added a third. (We hadn’t expected to find any marker here, until we started finding markers on other corners where they weren’t expected.)

Satisfied explorers. This time the trucks are easier to see (I used the telephoto right), directly above Archie’s head. We’ve come up some in elevation here, so they’re no longer right on the skyline.

We had reached the site around eight in the morning to find our first corner. By the time we hiked back through three dry washes to the truck and finally split up to go home, it was about two in the afternoon. So we took six hours finding four corners and marking some other spots along the borders. Not a bad day. Tack on a three-hour drive to get there and a three-hour drive to get home, and it’s almost like honest work.

Not bad for a Sunday lark!

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