Tim,
Two things that have really worked for us.
As you are traveling the country blow lots of cow calls, LOTS, I usually try to sound like a couple cows with a couple calves and a spike bull.
Often when a larger bull hears a small group like this moving through the country they will come to investigate. Often they will come in silently but sometimes you will get a bugle back.
Just use short high pitched spike bugles once in a while, but hit the cow and calf calls a lot as you move along. We have killed our last three bulls using this technique, two were trotting in at 40 yards and one at 100 yards as he was coming up to the trail we were on.
This is also a great trick to use if you come upon a herd in the timber and they go three separate ways. They will be looking to join back up.

If you come upon a very elk looking spot sit for 1/2 hour making these herd sounds and keep a sharp eye out for one sneaking in.
These techniques work whether the bulls or bugling or not.

The other is a small decoy, just a cows butt decoy or a cows head decoy.
Or even a shed antler works for this.

When you get a bulls attention and they hang up out there at 80 yards if you can wave the decoy at them or just stick a horn out and rake a tree where they can see it they will have their visual reassurance and likely come on in.

Remember bulls expect to see movement and hear noises when other elk are present. It won't put them off unless they can see you or smell you.

Do you guys also hunt the red stags in your area? I have seen hunts from your area on TV. Some of those animals are awesome looking.