Is there a distance minimum? Any other requirements?
As an example of a trail I think might be on the board I am thinking about the High Sierra Trail. It is only 50 miles. Work was started on it in 1928. It was the first trail in the Sierras to be built solely for recreational use. But I’m biased. It holds a dear place in my heart being the only trail I’ve done at least a significant part of almost every decade of my life. There is a wikipedia page at High Sierra Trail - Wikipedia