Luckily we didn't have to go through the swamp.
We made it to the location of Al Cat's Lounge around mile 4 of the course without any trouble, we hit the single-track that immediately follows but shortly thereafter we went wrong. After about 1.5 miles of wrongness we got back on course and made it to the location of Fast Fred's Cafe around mile 8.
We screwed up again and went way, way off course. The trails were still great for running but we knew we were off course and after a little back and forth and running in circles we decided just to head back in the general direction of the start/finish.
Eventually the trail started to look familiar and we knew we were back on course. We ran the last 2 miles correctly and ended up with a run that was just a little bit longer than the 12.5 miles of the real course.
We almost trampled a couple of big frogs on the trail but luckily didn't scare them off and I was able to get this picture. They were amazingly camouflaged so I tweaked the photo.
Below is the route we ran (red) overlaid on the actual race course (cyan) from when I did the marathon last year. We really screwed it up, but it was a fun run all the same.
distance: 12.7 miles
weather: high 60's to low 70's, clear sky
conditions: generally dry with only a few puddles, trails in great shape
gear: Inov-8 Roclite 295, Wright Socks, shorts, t-shirt, hat, Nathan HPL #20