Little John,
I made a 20 target course and used it for several years to sharpen up on range estimation, and to learn to ignore the topography. (shooting from one side of a small coolley to the other, and up and down will really mess with you for a while). It's an absolute hoot, and will really improve your hunting shots.
I made my targets from from old brown gunny-sacks filled with scrap pit-liner (probably any plastic sacks would work) do not put any aiming spots on the targets so people have to learn to" pic a spot". Also change the sizes just a little and you are messing with range estimation.....It's a real challenge in any event. Think you could put a cardboard silhouette in front of the matts and have a real nice and fun range.
The only problem is that when your walkin the land your mind will see real devious target locations and if you have ridges and draws put a bunny target across the draw, either up hill or down, and maybe 40 yards then make the bunny twice as big as it should be......on second thought ya might not be as mean as me, but it will get ya chuckling.
rich
PS: if you use broadheads the targets will have a very short lifespan, field points and or blunts will be better for the targets.