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.
A perk of majoring in wildlife biology in college is the plethora of hunting knowledge that you collect throughout your course load. One of the most important factors in whether an area can hold large quantities of animals or produce large antlers is forage.
Most universities, state schools and even community colleges offer basic botany courses and plant ID courses. Although it might not be feasable for the average middle age hunter to pay tuition and go back to college to learn hunting...