I know many of us consider ourselves to be ultra runners and also trail runners. I came across this organization: the American Trail Runner Association (http://www.trailrunner.com/).
The site looks like it has some pretty good information on it. Check it out!
HURT enjoys the privilege of partnerships with State and Federal agencies that hold the responsibility of protecting Oʻahu public lands. Those partnerships are based upon mutual trust and cooperation and shared concerns for the ʻaina. To keep that trust and continue to be provided the opportunity to host trail events, we (HURT) must understand and abide by rules that govern our partner agencies.
HURT does organize and facilitate official trail maintenance only when coordination with our partners has occurred. All trail work is performed under the supervision of a permitted individual with advance permissions. Some trails are off-limits for HURT to perform trail maintenance due to the sensitive flora. No HURT trail maintenance will occur outside of these parameters.
HURT and its partner agencies require that no self-directed trail maintenance occur on publicly-owned trails. Any individuals performing trail work outside of official HURT-organized events, are doing so on their own accord and will be held personally responsible by State and Federal agencies for any violations. Such activity could jeopardize our relationships with partner agencies and lead to inability to use public lands for our events.