On a hike near Mt. Evans my buddy and I came across a similar situation where we were downrange of a shooter. Some people decided it would be a great idea to shoot their rifle across the lake that we had stopped to have lunch at. They positioned themselves up in the rocks and fired several shots across the lake. Their line of fire crossed over the hiking trail, the lake where several people were boating, and into the granite on the other side. As soon as we heard the first shot, we moved to a more sheltered location in the large rocks we were having lunch on, trying to protect ourselves mostly from ricochet.
I never felt that they were shooting at us, but was incredibly pissed about the whole situtation. Looking back on it, I should have stopped at the rangers station on my way out and filed a report.
In the other posters case about the guys shooting at him and his wife across the lake, I wonder if the guys were doing the same thing as the group in my situation, just being a-holes and shooting in an unsecured location. They were probably scared poop-less when rounds began coming BACK!