I'm trying to get info on the terrain in units 5,13,131 and 441. I've hunted around montrose and pagosa springs and wanted to move up north but have bad knees and can't walk more than a mile or 2 miles. Any info I would appreciate.
I'd say most of unit 4 has fairly gentle terrain, as far as elk country goes. The national forest in 5 is reasonable too, the BLM in 5 is much steeper.
The public land in 13 is wicked steep, 131 I'm not sure about, as there isn't much public land. Just some STL I think.
Another unit with fairly gentle ground and decent roads is unit 70.
I'm not sure why you were interested in those units, but if it's because of the success rates, they can be misleading in units with large amounts of private land, unless that's what you're looking for.
When placing a trail camera don't just look for a well used trail. What you want to do is look for a freshly used trail off by itself that goes from a north facing ridge, thick forest, brushy knob or some other similar bedding area to a food source. Don't forget water sources. Especially in the summer months the deer need water so look for a good trail going down too a creek surrounded by thick cover and place the camera 100 yards up from the water source.
Scent control is very important...