I hear the warmer it is the higher to go. I am planning on making a trip out there myself one of these years. Archery tags are over the counter in most zones in Colorado. I'm not 100% sure on any of this but I'm sure you can do some research.
p.s. I do know that there is a number you can call and they will help you plan a hunting trip over the phone. Probably give you local campsites, license and tag info, etc.
Any info. you find out let me know because this is an interest of mine as well.
Get in the best shape you possibly can. A DIY elk hunt can be brutal. Colorado has over the counter tags and lots of public land. Look for pockets of public land that are close to or surrounded by private land. Also search for isolated areas with water. Practice calling and don't be afraid to be aggressive when you locate a bull. Invest in a quality pack frame and camping equipment. Make sure your boots fit well and are waterproof - blisters on your feet will limit your chances for success. Also practice so you are comfortable shooting at longer distances, as you can get longer shots out west.
Jae, you don't say what season you are going for, I'm guessing bow, or what state? You know there is also eastern elk up in the New England states.
I was plannnig an elk hunt to Idaho which my nephew lives near by, that fell through for this year, probably 2014, too much going on with my four hunting buddies. In the Boise natl park where we were going you could use quads or SxS in some areas. Think of this, there are many hunting zones or areas to pull tags for and the one I was focused on was 2000 sq. miles. I found a guy on a Polaris atv forum site who has a lot of good info. Maybe you could find someone on a board for what state you are going to. If you are going solo lots of luck, you need people with you to help and watch out for each other.