With a bit of digging further this link surfaced on the Denver Post site – with a note from the photographer suggesting the images were indeed genuine.
With information obtained on the Denver Post site and some lucky guessing, it was actually pretty easy to track down the fisher – ML – who happens to be on the pastoral staff of a church in the DFW metroplex. ML was kind enough to answer my ‘here’s a silly question’ email with this (and kindly offered permission to post it here):
“It was me, and the pictures are 100% authentic. I will forward you some of the others taken by a photographer from the Denver Post who happened to be driving by when the elk decided to join my friends and I in the river. There were a total of five elk with us. A cow moved into the river about an hour into our fishing trip (it was my first time fly fishing). The next cow joined her about 15 minutes later. We heard the male bugle, but my friend assured us he was up the hill on the other side of the road. 10 minutes later the third cow arrived, followed soon thereafter by number four. They stood together in a group about 25 feet behind me. A lot of people were stopping to take photos of us with the elk when I heard rustling behind me. The bull was twisting his way through the trees to join his herd. One of the cows walked between a friend of mine and I (we were 25 feet apart) and the bull kept eyeing us both to see what we were going to do (it was mating season, I wish I had known). The bull then walked up to the cow and nuzzled her. That put him about 10 feet from me and I knew it was time to move out.
I would be happy to talk to you if you want. I was blown away by the interest in the pictures. We made the front page of the Denver Post, an article in the Dallas morning news, and in Outdoor Life magazine. God blessed me with an incredible experience.”