Comtn,
With all due respect my snowbound friend, there's a reason several of your selections haven't "received any sort of recognition outside of local circles." They're not worthy!
Wellshire? It's an OK muny with some Ross buried deep in its recesses and fortunately some very evident, but IMO to be a hidden gem it very much needs a Ron Prichard Ross makeover a la the above-mentioned Wilmington NC Municipal. Then we'd be talking a gem, and not hidden either!
Denver City Park? One of the best views of downtown Denver anywhere and my favorite early morning quicky before work but c'mon--it's neither hidden nor a gem. Name one redeeming value on that course besides the view and its proximity to downtown?
Raccoon Creek? Maybe early in its existence but countless weak holes and it's been surpassed by at least a dozen others since it was built.
Mad Russian? OK, that qualifies but likely only for this GCA crowd. Anybody else playing it would say The Mad Russian farmer/owner who designed the course was off his rocker!
Can't comment on Saddleback and Spring Valley. In fact, I've never heard of Spring Valley, so at least it's hidden!
My hidden gem in Colorado is Grandote GC, a very fine Weiskopf/Morrish design in out of the way La Veta in southern Colorado. This summer it was laid bare by drought, only the greens were anything other than brown, and the firm and fast conditions only made me appreciate it more.
I've heard that Devil's Thumb in Delta on the western slope is also a gem, and it's certainly hidden, but I've not played it yet.
All The Best,