I hunted on a Colorado ranch that allowed cattle to graze in the summer. Occasionally there were a few left during elk season. I don't think the elk like having cows around. The cows do serve a purpose on that ranch due to their ability to trample down some of the high growth sage allowing tender grass to come up. The 17K acre ranch I hunted would allow 400 some odd cattle units to summer. As fall approached they would come off the summer 9 to 10.5K elevation and migrate down near the ranch entrance at 8K where they could be rounded up. After a summer on the mountain those cows were pretty wild.