There is a wiki page listing Colorado state highways 1 through 404. Unfortunately most the numbers are technical designation that overlap with other jurisdiction designations or have been retired or in some cases might have the state designation but have no actual signs listing the state highway number.
However a couple of the rural counties off the Front Range have numerous roads with just County Road designations and are not listed as ST. or AVE. If those are accepted I should hit the 50 required. One has been scored but a great number remain unscored. which might be just a backlog with the judges - that's a lot of photos submitted!
I did have one rejected for not including the actual road in the photo, which upon re-reading the rules is fair enough. If the county road signs are rejected for being like a residential street intersection sign instead of a shield-like highway sign further along the road...well that seems to me like it is not as clear in the rules. But at the end of the day all judge's decisions are final. This is high stakes Coddiwompling ladies and gentlemen so lets put on our big boy and big girl pants.....perhaps not in that order...and deal with it.
Like joepayne1950 the distilleries have been a hoot to check out. The Front Range is a target rich environment for hipsters with an entrepreneurial dream. Between Fort Collins, Denver and Colorado Springs I think I can complete the Drink to 50 Challenge!
There are many county roads with signage that reads Road 48 or whatever and those are not acceptable and get rejected. Those are not clear in the rules. The are signs that say County E 19 St and those get rejected despite the actual word "County" on the signage. I too had one rejected because you could not see the actual road.
Oh well. It appears I will finish this challenge with a 1400 mile trip for the last three numbers. My wife thinks it is all stupid. She's probably right.