Rocky Mountain Big Game Recovery has a website! So does United Blood Trackers.
https://www.rockymountainbiggamerecovery.org/
https://www.unitedbloodtrackers.org/find-a-tracker/
New app to connect hunters and trackers! https://gettrakr.com/
We have two tracking dogs in Wyoming who track bear, elk, moose, deer, and antelope. A little bit of rain on an old trail will "revive" the trail. Think of a dried up drop of blood on the counter, and adding a drop of water to it...it spreads out, which is exactly what the scent will do...