There's not a KOA in Golden. The Denver West KOA is a misnomer, as it's not in Denver, or really all that near Denver. It's actually in Central City. However, it doesn't open until April 24th.
The only places you'll find open, besides Cherry Creek and Chatfield SPs, are two parks in the Golden area that are open year round. One is run by the City of Golden (Clear Creek RV Park) and the other is a private RV park, Dakota West RV Park.
H E R E is the rvparkreviews.com site with those two, both rated as good. Clear Creek, in particular, is a hidden gem and should be considered.
ETA: I forgot about one in Wheat Ridge, which is in that same area. Prospect RV Park is also open year round;
H E R E is the link to the reviews on that park as well.
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