Greg, here is a link to Rockie Jacobsens bugling bulls and beyond instructional series.

Rockie is a not on only a world champion elk caller, he is a resident here in Idaho and gets it done on public lands. I've met Rockie, hes a great guy, he really understands the different levels of elk vocalization. His DVDS are excellent instructional guides for learning how to successfullycall ineven the most pressured bullelk.

http://www.trophyshotsports.com/products.asp?cat=17