Old Cemetery

I've probably mapped about 2000 acres of the park now (only a thousand more to go), but today I found the first cemetery. It is way out on the east map, on the other side of the creek, high on a hill. Not very far from the southeast boundary, but difficult to get to. It looks very similar to the graves at McIntosh Reserve, another of the GAOC orienteering maps, which is just across the border from Chattahoochee Bend.

There are four graves, marked by rock slabs above ground:

From Chattahoochee Bend

From Chattahoochee Bend

The largest one is open on the end - you can see inside:

From Chattahoochee Bend

But sorry, no bones:

From Chattahoochee Bend

A Week of Mapping

Took a week off from the real job to attempt to get as much done on the east map as possible before the leaves come out. Once spring arrives, mapping slows down because of the reduced visibility.

It's been an exhausting week, and it's not over yet. Let's see if I can remember what has happened so far!

Saturday 3/13/10: Finished the eastern side of the big ridge of rocks. For some reason, most of the boulders are on the west side of the ridges. On the eastern side, there are more bare rock areas, some of them ending in cliffs.

From Chattahoochee Bend

Sunday 3/14/10: Went orienteering at Joe Kurz!

Monday 3/15/10: There's a large shallow reentrant east of the big ridge that's about 400x600 meters. It's pine, logged at some point in the distant past, terraced by some poor farmer (or slaves?). Visibility is poor, but it's not green. Naturally I saved that reentrant for later in the week. I extended the big creek all the way out to the northeast corner of the map. Measuring all the twists and turns, it's 2.1 km. Straight line, it's only 1.5km. It gets bigger and bigger the further northeast it flows.

From Chattahoochee Bend

Tuesday 3/16/10: Time to finally fill in the big shallow reentrant. Not an easy task. There is an old logging road that is barely visible that circles through the reentrant without actually going anywhere. It leaves almost no trace on the forest floor, so it doesn't show up on the lidar contours, yet is is easily visible to an orienteer. So I spent considerable time trying to get it accurately located. After that, everything went smoothly. Here's an example photo of what the road looks like, as it is crossing a small bare rock area:

From Chattahoochee Bend

Wednesday 3/17/10: There's a knob of map that extends north of the big power line on the east map, about 550x800 meters, although part of it is only 250 meters wide. It's plenty big enough for running into and out of. And it is jam packed with rocks. This was the day that it rained, so I spent half a day running up the western boundary before the wet drove me off.

Thursday 3/18/10: Volunteered with the GATC north of Neels Gap for the alternate spring break program - I am on vacation after all.

Friday 3/19/10: A very long day. Finished the knob of map. Lots and lots of boulders up here, but the pattern of big rocks on the west of the ridge and bare rock on the east continued. Here's a big hill of boulders:

From Chattahoochee Bend

And here's some bare rock:

From Chattahoochee Bend

Saturday 3/20/10: I'm taking the day off from field checking. Lots and lots of drafting to catch up on. I've mapped everything north of the big creek. I still have two days left of vacation (Monday is off too). Can I finish everything south of the creek in two days? Stay tuned.

The Big Creek

All the big geological features in this section of the map run southwest to northeast, so it's no surprise that the big creek runs - southwest to northeast. I don't know where this creek begins, because it does not cross any of the roads south of the map. It's pretty big for having such a short run. It crosses the road on the northeast corner of the map on it's way to the river. How big is it?

From Chattahoochee Bend

Not as big as the creeks at Cochran Mill. More the size of the creek at Pickett's Mill. There won't be any problem crossing it during normal water levels - although you will get your feet wet. Here's where one of the old roads fords the creek:

From Chattahoochee Bend

My plan is to finish everything north of the creek before crossing it and mapping the other side. At one spot there is a very nice beaver swamp and impressive dam:

From Chattahoochee Bend

That's the dam in that photo bending across. I thought maybe I would get a break from the boulders down in this section, but it's not to be. There are some huge rock gardens that are awaiting mapping:

From Chattahoochee Bend

From Chattahoochee Bend

Map Sample

Here's another map sample, this one with a variety of bare rock and boulder features to ponder, including a couple of boulders drawn to scale (the black blobs). Click to see the whole thing:

From Chattahoochee Bend

Boulders, Boulders, Boulders

From Chattahoochee Bend

Boulder count is about 300. Ocad (the map CAD software) has a feature where it will count all instances of a symbol. 300 seems like a lot, but it's not really. The Red Top State Park map, by comparison, has around 1500 boulders. Of course, I am still not halfway done with this map, so the number of boulders will certainly climb. What is unique about Chattahoochee Bend is that the boulders are not evenly distributed (like they are at Red Top). They are in bands, running across the map. And they are much larger than the boulders at Red Top. The largest I have found so far is 16 meters by 20 meters and 5 meters tall. That's big enough to be mapped "real size". Instead of using a black dot or triangle, the boulder is drawn in black to scale on the map - impressive.

From Chattahoochee Bend

From Chattahoochee Bend

From Chattahoochee Bend

From Chattahoochee Bend

From Chattahoochee Bend

It is also very challenging to map so many boulders. I spent five hours on Saturday doing an area only about 300 meters square. Deciding what not to map is very important, as is deciding which symbol to use - small dot, large dot, triangle, irregular triangle, or mapped to scale. Here's a small example:

From Chattahoochee Bend

Between Snowstorms

Big snow yesterday, Saturday 2/13/2010. Probably about 3 inches on the map. So I waited for it to drip off the trees and melt away before heading out there today. Forecast for overnight is even more snow.

From Chattahoochee Bend

I am almost done with another page of the basemap. Worked my way down, down, down and discovered a little pond in the bottom corner of this page.

From Chattahoochee Bend

I cannot figure out the pattern of the boulders. It's either feast of famine. There were dozens on the west side of the spur I am working on, and two on the east side. They are in bands. Once the map is drafted that will probably be obvious, but it's certainly puzzling to the poor mapper while he is out there trying to plan the best use of his time!

And the next spur to the east is covered with more bare rock areas. It looks as if the big shallow reentrant repeats again three or four hundred meters east. But that will all be revealed over the next few trips.

Measurements and Accuracy

Now that I am mapping boulder fields I thought I would describe the process of how I measure the distance between boulders and place them on the field notes. This process works for anything that needs to be measured.

I use a metal ruler, six inches long, with one edge metric and the other in inches. (Take a compass with you when you buy your ruler so you can pick one that is non-magnetic.) The first thing you do is take some blue painters tape and mask off the inch edge of the ruler. Nothing is worse than using the sixteenths by mistake when you want millimeters. Been there, done that, wore out an eraser.

Know your pace count per 100 meters. Not the running pace count that orienteers use, but walking at your mapping stride. Mine is 61 double paces (count only the left foot) per 100 meters.

Make a simple chart with paces in one column, millimeters (at your map scale) in one column, and meters in a third column. I print out my chart and tape it to my map board. Here is the chart I use. You can look at the formulas and see how I calculate everything.

Now how do you use it? Starting from a boulder that you have already placed correctly(!), count your paces to the next boulder. Use your chart to convert that to millimeters. Use your ruler to measure the distance on your map and make your mark (in the right direction, of course).

You can also use the chart to convert from meters to map millimeters. I sometimes carry a laser rangefinder, which can save a lot of steps. Instead of pacing to the next boulder, I use the gadget to tell me the meters, and convert that to map millimeters using the chart.

Why does the chart round off the millimeters to 0.5? Because you really can't make a pencil mark smaller than that, and more accuracy is not always a better thing.