Our son and his wife live on the northeast side of Denver (I-25 and 135th St.). We have stayed at St. Vrain State Park which is a short distance north of there. The sites are generous in size but to get to the full hookups you must travel on interior dirt roads. We made our 2013 reservations online.
This park may still be closed due to flood damage but they are attempting to reopen soon.
Fred & Mary RVM135
2012 Dutch Star 3735 ISL 400
2012 GMC Sierra Ext Cab 4x4