Picture very helpful. So was the article.
So he fell 50 feet INTO a steep chute. That sounds like he went off into space for 50 feet, off of something and into nothing....sort of like....a cliff.
Wow, now I have to guarantee results. That's a high hurdle.
I don't think a sign is the way to go, but I think a little delineation of trail path would be reasonable. I know I've only spent 12 years building trails on forests, but it seems that this is a common remedy for such situations that I've had to do, what, 100 times? So I think it is likely to work.
In my regular line of work, if I had to wait for certainty to do things, I'd have a lot of blood on my hands.
Guarantee? Sure, I'll give a guarantee. If it doesn't work, you can cut the pay I get for the thousand or so hours of volunteer work I've done on trails, in half.
I'd start with a site assessment, including considerable observation of hikers making their way down. Generally, I'd consider using the techniques discussed in the official Trail Notebook, starting on page 128:
USDA Forest Service Trail Maintenance Notebook
