That's exactly what I did with mine RC. To install them I put a step ladder in the back of the Polarius Ranger bed and stood on the step ladder. Mine are all at least 10 feet up. Plus I cut of the branches below the camera (mostly to reduce false triggering from the motion of branches).
To get to my cameras you'd either have to bring a ladder or cut the tree down.
Nothing will absolutely stop trespassers but in my experience the more deterrents you add the better off you will be.
If you get one of these tough Texans that brings their own chain saw well basically you're screwed.
