When I was the SWAT Team commander for my department, I saw a good need for being able to read trail signs and most of all the tracking of humans in the wilderness.
Since I live in a border State, I contacted the U. S. Border Patrol and asked if they had an expert, that could teach us the basics of tracking people in the wilderness. They supplied an officer who, indeed was an expert tracker.
We didn't become experts; however, when he got through with us we knew a lot more then we did before.