Every year I take a few trips to Estes Park to see the aspen trees turn bright golden yellow and if I'm lucky, watch (and hear) the elk rut. The combination of a deep moan and high-pitched whistles can be heard echoing all along the Front Range region and is kind of freaky the first time you hear them but once fall starts, the echoing bugle of the elk signals the mating season to the herd. It's a spectacular sight as these guys are as large as my car! And you have to be careful, they get easily agitated and I've seen a few actually charge people. One time it was a golf cart with 4 golfers in it! Worth the trip, put Estes Park on your bucket list!