Register | Login
Attackpoint - performance and training tools for orienteering athletes

Discussion: Map Analysis -- How would you get to the control point?

in: Orienteering; Training & Technique

Jan 23, 2023 7:08 PM # 
I am a beginner orienteer who, at my last orienteering event, started breaking into low intermediate skills -- judging by the ease with which I found controls that normally I would have not found.

I thought it might be good for my skills, and the skills of others to analyze a map. Here is a link to a map of a permanent course in Kentucky. What route would you take to get from the starting point to control 1 using the Control Attack Route (CAR) method?
Jan 23, 2023 7:57 PM # 
I'd take the trail. My attackpoint would be where the trail intersects with the stream (also looking for the distinct tree or rootstock, whatever that green X to the right of the trail is). Take a bearing from that trail / stream intersection.
Jan 23, 2023 8:13 PM # 
What is the control description for 1?

Brooke gave you a good route. That's probably what I would do.

Another possible route would be to take the trail to the trail junction (possible attach point). Turn North/right and continue to the 90 degree turn (attach point). Take a bearing from that 90 degree trail turn. As a back up you could use the next Y trail junction as an attack point.
Jan 23, 2023 8:33 PM # 
I concur with Brooke - down the trail at speed, when you hit the trickle, look across the reentrant for the larger trail beyond, then drop into the ditch - which I suspect might hide the flag until you're right on top of it. You should probably be able to see the lake below and estimate how far up the reentrant/ditch you want to aim for. If conditions are dry, you might miss the trickle, but should still see the lake and reentrant in the white woods.
Jan 23, 2023 9:15 PM # 
Pink Socks:
One thing to note is that the map has a date from 2012, which means that I'm not 100% trusting the Green X, (there's no legend, but I'd guess it's either a rootstock or stump). The rootstock is very likely still there, but other trees may have fallen down over the last decade, meaning that there could be other rootstocks along that trail that could confuse.

Control. It looks like maybe a bend in a gully. In any case, it's going to in/along the lowest part of the reentrant (valley). The control also has a very strong, very close backstop feature of a trail intersection featuring a very large trail coming down the hill from the west. That trail looks like it's only 10-15m beyond the control.

Attackpoint. It's a bit of a "soft" attackpoint, but I concur with Clint. Look ahead and see if you can see that big trail coming down from the west. Maybe you'll notice the rootstock, maybe you'll notice the trickle, but I wouldn't worry about those if you miss 'em. Key in on that large trail coming down, and when you see it, then estimate how far away you are (if you spy it from a long ways away, you don't need to jump off the small trail just yet). As you approach, jump off the trail and aim for the where the end of that trail is at the lowest spot in the valley, knowing that the control is just ~15m 'upstream' of that location.

Route. Down the trail. That hillside is relatively steep and there's vegetation, but there happens to be a very easy way to get down that takes you 90% of the way there.
Jan 23, 2023 9:51 PM # 
Thanks everyone -- I thought of the attack point as the intersection of the stream and the trail like others.

Now, using the same map, how would you traverse the distance from control point 7 to control point 8? I am especially interested in how you would traverse the long distance, as well as how you would reach the control using CAR.
Jan 23, 2023 10:35 PM # 
I would go up and around to the left, possibly up to the trail if the yellow wasn't easy running. You are going a longer distance but with much less climb and easier running.

I likely would leave the trail and head in at the reentrant, using the dark green in the yellow and powerline over the reentrant to lead me in, but if the green was particularly bad one could also go on the trail north of the control and cut off when I could see the bend in front of me, and use the change from dark green to light green if it was visible. The good thing is that you are headed off the trail to another line feature that you shouldn't be able to miss (the ditch) so you can also aim off, purposely getting off the trail a little early so you know you have to go down the ditch some or getting off too late so you know you need to go up the ditch slightly. (so attack point is a little tough but I would estimate distance from the trail bend and the powerline crossing)
Jan 23, 2023 11:48 PM # 
First of all bwardmusic aren't you supposed to be in Florida?
Second CAR is good but have you ever heard of the concept of enlarging the control? The control is in the middle of a valley in open woods. When convenient get to the middle of the valley and run down beside that 'gully' (Hate that symbol being used for more than a short distance but it is what it is)
If the control indeed is down in the gully then anyone running at it perpendicular to the gully runs the risk of missing it to one side.
Jan 24, 2023 12:27 AM # 
First rule in orienteering --- do not waste time on trying to design a perfect plan.
It never pays off. Use your common sense and intuition.
Use your compass to take the direction, slightly to the right, and run in that direction. It you see a trail on the way, you can follow it, if not ---no problem, get to the bottom of the ravine, and run along the ditch downstream till you see the control. If you miss it --- you get to the edge of the water, likely with a lot of floating garbage. Take a moment to swear to release your frustration, then turn around, and run back to the control.
Jan 24, 2023 12:37 AM # 
For 7-8, it's trail the whole way, easy call. If the semi-open looks really good, you have the option to cut the corners.
Jan 24, 2023 2:29 AM # 
Are you sure that's a US orienteering map? The scale is in 'meters' (whatever they are) rather than miles.

I'd personally be trying to avoid going into the woods so as to not encounter any bears or the people who shoot bears.
Jan 24, 2023 3:41 PM # 
CONTROL: The control appears to be in an erosion gully just south of a trail. The trail crosses a powerline just NW of the control and makes a bend just east of the control. Vegetation in and around the erosion gully is green, on an older map, so how thick it actually is could be variable.

ATTACK POINT: the trail crossing the powerline seems like a good attackpoint.

ROUTE: The straight line has lots of ups and downs and thicker vegetation. I'd use the flatter and faster roads and trails to the west, but I'd cut the corners depending on how open the "rough open with scattered trees" (yellow with white dots) actually appears. Once on the trail at the powerline, I'd be looking for the easiest way to get into (or next to) the erosion gully and follow it east. If the woods between path and gully continued to be very thick, I'd keep moving along the path - if I got all the way to the bend, then I'd have to tough it into the woods and back up along the gully, regardless of how thick. Since this is a permanent control, there's a good chance that as you get alongside it on the trail, you'll find an "exit path" where people leaving it have made the shortest beeline back onto the trail.
Jan 24, 2023 6:24 PM # 
@gordhun -- I used to be in Florida but my wife insisted that I move to Clarksville TN. There is a new club in Nashville that had a good course on the weekend, which got me fired up again, but they are new and events are not frequent yet. The closest readily available orienteering I have found so far is 2-3 hours away in northern Kentucky where there are permanent courses.

I REALLY miss Florida. There are so many courses there, particularly with the ROYO (Run on Your Own) semi-permanent courses that came into existence as a response to COVID.

@tRicky: It's definitely a US Orienteering Map. It's of Rough River Dam, a state park in Kentucky.

Thanks to everyone with the analysis you're doing. I'm learning a few things from all of you and I appreciate it. I hope you can keep it coming!
Jan 24, 2023 6:29 PM # 
From 7, why not follow the big black trail to the west a bit until it intersects with the powerline. Then just follow the power line until you hit dense forest, follow the boundary of the dense forest, and then hook back up with the power line (which should be easy to see being up in the air) all the way to the intersection of the power line and the black trail near control 8. Then use this intersection of the power line and black trail near 8 as your attack point?
Jan 24, 2023 6:37 PM # 
@bwardmusic That map is out of date. Lots of work has been done on the dam and other places. Are you aware of the Nashville Orienteering Club? They are closer to you. Edit: Sorry, just read your post from above
Jan 24, 2023 6:55 PM # 
@Brucewithamap: Too bad that the map is all we have right now. But I appreciate knowing it's out of date. Yes, Nashville is new. They are well-organized and doing a great job with their events, but they aren't frequent yet, probably due to a combination of manpower and the need to develop maps.

Everyone, if you are willing, would appreciate a reaction to my proposed route a couple posts above this one....
Jan 24, 2023 7:30 PM # 
IMO, wife should not unilaterally make important decisions for you

But now that you are in TN, focus on good things vs FL

1. No alligators, pythons, those creepy snapping creatures from hell, no banana spiders.
2. In Clarksville, you can do off-trail running in Dunbar Cave park, a neat little park with some karst features, you will not get lost there even without a map. Rotary Park is another decent place with trails. LBL is not too far away
Jan 24, 2023 7:50 PM # 
@yurets - Agreed on point number 1, but there is more to the story than I can share in a public forum....:(

I don't miss the gators or the cottonmouth snakes from Florida. We had run-ins with both when my children were young and they could have been fatal. The other parks are nice in Florida, but without orienteering control points they lack attraction for me. I have map-making skills -- but only at the tracing, not the field level very much. Part of me wants to create a permanent course at Rotary Park. But the field work of mapping seems tedious to me...
Jan 24, 2023 8:07 PM # 
About the route 7-8 Brent. If you are going off the straight line to get to the power line you might as well go all the way to the road. The reason? The footing and therefore the speed you can muster will be much better on the road than on the broken ground of the power line. (Some say it as much as 5:1 but I pick a more conservative ratio than that) Then at one point along the power line you will have to go down a slope and then almost immediately back up. The time you lose going up the hill is not offset by time gained going down the slope. Some people like me also lose time on steep downhills compared to the flat.
Jan 24, 2023 8:08 PM # 
From 7, why not follow the big black trail to the west a bit until it intersects with the powerline. Then just follow the power line until you hit dense forest, follow the boundary of the dense forest, and then hook back up with the power line (which should be easy to see being up in the air) all the way to the intersection of the power line and the black trail near control 8. Then use this intersection of the power line and black trail near 8 as your attack point?
Jan 25, 2023 5:54 AM # 
Why not just run on the road? It's Right There. It's flat. It's fast. Hurrah! You can also think about your next route choice (8-9 I'd run on the road also probably, actually I'd run on roads/tracks for nearly all of them just to save the hassle) instead of tripping over your feet.

wife should not unilaterally make important decisions for you

This is how I ended up in stupid Melbourne.
Jan 25, 2023 8:34 AM # 
I like Gord's analysis above about the time saved in distance being offset by the slowness of rougher terrain. Upon reflection, I think one of the reasons I did so well last weekend, and felt I had "graduated" a bit up the skill ladder was I took easy longer routes rather than shorter ones through rougher terrain. Thanks Gord...:)
Jan 25, 2023 10:50 AM # 
Brent. Imagine that you are a gold miner. It is 1848 and you are heading inland from the San Franciscco Bay area. You are about to hit a bonanza. That is what it should be like to be an interested orienteering mapper in Tennessee, any part of Tennessee. I'm convinced the state has some of the best , rugged but best, orienteering terrain east of the Rockies and south of the Mason-Dixon like.
You do not have so many alligators but you do have hunters and moonshiners to contend with. Nonetheless I think thanks to the TVA, etc there is lots of public land around. The state-wide available free LiDAR seems to be very good quality. That means that even before the field work stage you can turn out pretty good orienteering maps, maps that everyone from Adventure racers to scouts to home schoolers, to everyone but orienteers would be happy with. Field work can capture the rest.
I'll send you an e-mail showing the steps to painlessly put together an orienteering map of Rotary Park, all without leaving your computer.
Jan 26, 2023 5:38 PM # 
Terje Mathisen:
I'll second @gordhun here, I got interested in TN lidar when I started hearing about the Barkley Marathons, wanting to make my own (much better?) map over the racing area and see if I could reverse engineer where (most of?) the controls were actually located!
Jan 29, 2023 2:31 AM # 
Yeah! Dunbar Cave State Park? It's pretty tiny ...

Dunbar Cave—Clarksville, TN

Super-quick, super dirty. :) I also did all of Cheatham Wildlife Management Area (very big!), but have no idea if you're even allowed to go there.
Jan 29, 2023 3:48 AM # 
That is not 1:6000, LOL. Close to 1:20000
Jan 29, 2023 5:55 AM # 
Haha, yeah, the displayed image is indeed not 1:6000 ... it is was 1:12000, now it's ~1:8108 (hah), if you open the image and print it 100%. And the PDF it links to is was not 1:6000 either ... I had changed the scale to better-fit the paper, and didn't update the text. It's 1:7500. Updated both.

Plenty of other issues, too, with the feature selection of my half-a**ed CRT files. Get what you pay for, I suppose. :)
Jan 29, 2023 6:04 AM # 
Here's a resized by ... a lot ... Cheatam Wildlife Management Area KP map ... no fiddling. That area looks ripe for a rogaine.

Frozen Head, next? Did you ever complete the project, Terje?
Jan 29, 2023 12:36 PM # 
Yeah, that's what I want, a rogaine in an area full of saw briers.
Jan 29, 2023 4:25 PM # 
Don't know about WMA, but forest floor in Dunbar Cave is densely covered by goutweed, which is edible,
Jan 29, 2023 5:21 PM # 
What other park(s) around Clarksville, TN to do? I'm not familiar with the area. Frozen Head running ... now! 134 / 141 tiles: complete. :fat:
Feb 1, 2023 11:26 AM # 
@Hughmac4 There is a Rogaine and AR scheduled for the Cheatam Wildlife MA scheduled for Aug
Feb 1, 2023 1:10 PM # 
@Hughmac4 Hopefully I can check Dunbar out in person. Maybe next week. I will import that lidar generated map into my tablet and see how well it matches. Thanks

This discussion thread is closed.