Back in the mid 90's a buddy and I were archery elk hunting not to far from Snoqualmie pass. We were hiking straight up a mountain and making alot of noise when all of a sudden a bull bugles within 100 yards of us, we get set up with my buddy in front and I started bugling, he immeadiately responded but wouldn't come in so I grabbed a large branch and started raking a small tree and bugle again. This got his attention and he came in fast and stopped about 3 yards from my buddy, and perfactly broadside to me. I didn't have a shot with my buddy being so close so I tried cow calling to get him to turn and give Dave a shot, he spooked and ran off the way he came.
Dave and I didn't think he had made us and thought he might not have gone far, we followed his trail a short distance then decided to stop for lunch and regroup, we were sitting about 15 yards apart with a small draw seperating us. I decided to spray a couple shots of cow in heat scent which I was carrying and the breeze carried the scent in the same general direction we had last seen the bull, within about 2 minutes that bull came in on a dead run and skidded to a stop right at the base of the small tree I was sitting under, I could have slapped his nose with an arrow, unfortunately, this time I was to close for Dave to get the shot, the elk and I had a stare down for about 10 seconds then I blinked and he bolted, that was the last we saw of him.
Yes, I am a believer in cow in heat scent. That was also the biggest bull I've seen during an open elk season, 6x6.