The kids and were playing outside this evening and my 1.5 year old dog treed a squirrel out behind the house. I went and got my rifle but it had hidden by the time I got back. It was nearly dark and was back in some thick pine trees. He stayed there barking...

What's the best way to train a dog for treeing squirrels? He obviously has interest and I'm excited to get him out this weekend.
In any moment of decision, the best thing you can do is the right thing. The worst thing you can do is nothing.