Another snowstorm is on tap for this weekend. That's 5 our of the last 6 weekends we've had storms. If the route isn't covered in snow, it's going to be very, very wet. The only areas that may luck out in being dry enough are perhaps South Park proper (don't even think of Boreas Pass, or even the pass into Salida), and perhaps Del Norte and a few miles N of it. I've been stuck in a snowstorm in South Park on the route, and it's kinda miserable. The soil near the Indian Hills is very muddy w/clay.
None of this should effect the Grand Départ in June, except for perhaps a bit of snow/wetness up at the highest points of the passes.
If you're looking for a shakedown ride and want to go to CO (or need a backup), perhaps something like the Anti Epic route (which you can find here
http://coloradogravelroads.com/). If South Park is clear enough, another option would be the Dirty Double Fondo, ~half of which is the GDMBR, the rest is a really great route (much better in my opinion). You could do it in one long day,
https://coloradoes.wordpress.com/swes-event-list/ddf200k/The race itself is on May 21st! I've done it twice, great time and Salida is a hell of a town. Maybe I can make it back this year
