Re: Conejos river colorado ? trip in late june
I'd stop at Fox Creek Store or Conejos River Anglers on the way in (I'm assuming you're taking CO 17 eastbound from US 285) and ask them what's popping. CRA also posts periodic reports; look for the reports online, they talk patterns and what's working in them.
Stoneflies will probably be going strong that high up the river at that time, but I'm certainly no expert on the Conejos: the aforementioned folks are.
That said, it's a wonderful river in some very beautiful country. I plan on being on it mid-June myself and perhaps a couple more times during the year - but it's only a 2 hour jaunt from here.