I think he's stating that the trail might come to a terminus 1 km away instead of continuing past 1 km away. That's probably not what the puzzle-maker intended, though.

Mmm.. well, so far we all seem to be wrong.

I don't know the exact answer, but it is *around* 6.4KM total length, as measured by me today out in the field (found the cache anyways, but it took a bit of looking).

Now.. I wonder how to calculate the correct answer?

I'm interested, too! I looked around and found this thread on Google groups in the rec.puzzles newsgroup. There are a few solutions there, and one solves to 6.397. It seems that all the solutions are somewhat horseshoe shaped, but you need some more complex math to solve them. My solution it seems is not optimal.

That's hilarious! My *actual* field measurement was 6.398KM..