Elk are big, hang out in large groups, leave plenty of sign and are fairly easy to spot if you go slow enough and use binoculars from vantage points. The areas in Colorado I have hunted didn't have the type of trees that are needed for tree stands and like has been said unless you found some remote water, sitting in a tree will just ensure you probably won't be seeing elk. I would buy a decent pack frame and either hunt with it or at least have it in the truck or remote camp. Once you get an animal down a pack frame will help you get 50 to 100 pounds of meat out each trip. Elk are large animals and even a cow will present a difficulty when trying to cool the meat and get it out of the canyons. Altitude sickness is another consideration. I live at 118' above sea level and the cabin I normally stayed in was somewhere around 9000 feet and we hunted higher. I had 1 issue with altitude sickness and then started to use an approved and prescribed medicine to condition my blood to operate in reduced O2 levels. It had a few minor side effects such as tingling lips and finger tips and making carbonated beverages taste bad but for the most part were helpful. The med was to be taken a couple of days before arriving at altitude and then for a day or two after. The side effects ended a day or so after I stopped taking the med. Not everyone experiences altitude sickness but once it happens the hunt is over since you will experience acute flue like symptoms and getting to lower elevation is necessary. The med is commonly used by high altitude military foot soldiers but in higher doses than what you would be prescribed. The pictures posted above are fairly typical of the terrain where you might find elk. Good leather footwear is necessary for climbing up and down those rocky canyons. Don't cheap out on the boots because they need to be comfortable and offer good support. Learn to use a cow call because on several occasions when a herd of elk got suspicious of me moving through the timber a cow call calmed them and they went back to feeding. If you jump a herd start cow calling right off and sometimes it will slow or stop them but not always. When they run off they are usually gone for miles unlike deer.
Nice Colorado elk flags.