
Elk in the area I hunt are pretty tight lipped. They rarely respond to locator bugles but they do come in silent pretty often. I hear a lot of guys pull up, let out a bugle or two, if nothing responds they drive off thinking there are no elk in the area.
The last couple years I have been hunting them just like I hunt predators. Set up a stand covering where I think they might come from and start calling. Switch between cow talk and various bugles for 30-40 minutes. If nothing comes in I move about a mile and do it again. I know they are in there...somewhere.

I have had great success with seeing bulls and this year I finally got an arrow in one. I called in 5 confirmed bulls this year doing this. One was the biggest Roosevelt I have ever seen (Calling for my dad but he could not get a shot). He never made a sound until he was right on top of us. Of course there were dozens of stand where nothing responded but all of my hunting was done within 3 or 4 miles from my camp.
Thought I would share my strategy and video. Hope it helps.
http://youtu.be/02_oR3_EGV0