Before going to Dillon Pinnacles, I noticed one map shows the trail to the pinnacles (and a couple interpretive signs) while another shows a trail up Dillon Gulch. This trail predates the reservoir and just goes to a spring. (The map actually showed it just randomly starting at the water with no entry other than boat.) I found it signed and it is easy to trace all the way to the spring and no further as advertised. The sign was specifically giving the dates. The land between the NPS and USDA is state wildlife, I believe, and they don’t want you up there for the big game migration in late winter, early spring. And now you know from the map.