First off, thee is NO 4th season (Nov 12-16) deer tags in either unit. I just did a quick check of the reg booklet.
For elk in the 4th season you have to apply by 4/1. There is tons of blm land in unit 70 that would be good elk hunting. CO has a lot of elk, most of the bulls are in the 2 1/2 yr age class and will be raghorns. By the 4th season a pretty large number of those will have been harvested by the archery/ muzzy/1st rifle/2nd rifle/ 3rd rifle. I am familiar with unit 70 and if you are set on the 4th season, I would say take a look at pony draw/dry creek basin/monogram mesa just because that is the area I am most familiar with.
peanut