Here is the thread that was started quite a while ago. But until they either come up with pictures, or the dna of a grizzley it is all speculation. I know of hunters that see a big brown faze black bear and swear it is a grizzley just by its size. A good test to tell the difference is on the Montana's gane and fish web site. You have to pass it to get a bear license.
there have been reports of Griz in Colo for years, back in the early 80's, when in collage at Durango, spent a lot of time around Wolf creek, the old timers up there (made friend with a old, old goverment cat hunter) said there is good population on Griz up there. There was a gris killed by a bow hunter in the 80's in the San Jaun's, it was all over the paper, guy spent some time in the hosp.
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...