Bob,
If you want to see Elk in CO now, you need to have very good knee's. It's 8 am and it's already 80 degrees.
Expect to find them very high up. As SS mentioned, during the day they will be in dark timber. They will graze at night when it's cool. I'd set on high altitude water sources near dark timber and good grass as sun up and sun down. That would be your best chance.