In the 70's and early 80's there was pretty darn good hunting around Delta and Olathe, but it's all leased up now and there are fewer birds to boot. There are a few in the lower Grand Valley (like Horsethief), but not really worth the effort, I don't think. Never heard of the ones by Meeker, but don't doubt it. I think if I were you I'd be thinking more about Idaho if you're looking for a closer trip. Otherwise, if you're coming to eastern Colo (Denver and east), put in the extra hour or so and make it to the eastern tier of counties in Colo - there's a lot more birds than in the western edge of their range here. You might have an hour or two less time hunting, but you'll be in a bird population at least twice as dense! This is assuming you're looking for wild birds/unguided hunting.