Discussion: 2 things

1) We swam from TA1 and never found the 'trail' that you describe as fewer trees and ferns. I think I might have walked across it, but was expecting something more like the last 15k of roads we biked into the TA on. We then walked east to try to intercept the road, but didn't see it so we aborted that plan, swam to the east side of the lake, and traveled south to get to CP 4, but didn't see the trail that you took to get there.

2) We did the opposite as you from CP 5 to the road. We ran the shore around the peninsula you trekked over, then get up high and to the east of the lake. We moved really fast here.

Yeah, the orange line varied wildly as to what it represented!

I appreciate the comments - it's very insightful to see how the top folks do it.

You might enjoy reading Dave Hitchon's (FB's) report.
http://ar.attackpoint.org/viewlog.jsp/user_2827/pe...

He may have been the racer at the event with the most years of AR under his belt, and he has also designed courses. In his report, he made some comments about how he worked with those trails/roads based on his past experience with the reliability of such manmade features.

Because the map was based on 1988 info (I think U.S. map data is usually newer?), some of the snowmobile trails have been re-routed, and some of the logged areas no longer have trucks passing through. Mother Nature takes over surprisingly quickly, as you noticed. (Good on you for realizing that smaller trees and ferns could be an old road!) Conversely, there are new trails and roads that have been built since the map was made. So an orange line may be useful and it may *not* be useful since a lot can change in 25 years. Generally, it's safer to work with water features and contours up here when you can, and if a minor mapped road doesn't seem to have a purpose (e.g. an obvious destination), be particularly suspicious of it.

In Bob's races, some of the most reliable trails are the bold black dashed lines that he adds manually because those are based on recent GPS tracks from our course testing.

No, our USGS maps in Michigan are usually also 1980 something. We have a lot of two track that is there in the forest and not on the map, or two tracks that are mapped and are in varying states of fewer trees. Some of us occasionally get spoiled by o maps and whine a bit more than we should - the contour lines haven't changed much in either case, although generalizing to WT interval is a skill to work on! Many of the Michigan maps are ~3 m.

The thing I learned about your Canadian maps was that the little pond connecting streams were super reliable, or it seemed so anyway. It might be 0.5 m to step over, but gosh it was there and right. A previous racer and local director (Infiterra Luke) said to use large water and a compass as much as possible, and he was spot on.

Wow - 3 m contours. We rarely get that even in orienteering. Large water is good advice - keeping in mind that beavers can make a dry area wet over the years and vice versa. Those streams can be helpful although you still have to know your position reasonably well because there are plenty of streams *not* on the map too. It sounds like you managed to stay on top of that. I do lots of orienteering too and definitely have different expectations of maps made for that purpose!

We hit that bridge out/under construction as well and were equally confused. I believe it was about 1km north from the trail intersection just south of Wilson Lake.

I would buy that - looks like a bend in the orange trail, and our tracking shows us slow there, and your route also goes through that area.