We stayed 2-3 weeks every summer from 2004 to 2014 at Fun Valley Family RV Resort just west of Southfork, CO on US 160. South Fork of the Rio Grande runs about half mile thru it. It is a family oriented park with lots of activities for kids and an enjoyable place for adults as well. Lots of us old f@arts stay there. We went with our kids, grandkids, and various friends. But it can be a very busy place that some people do not like. But end of August early September it slows down with most kids in school. Gated entrance, paved roads, but packed native soil sites that, with a few exceptions, do not really get muddy when it rains. Resort refers more to the numerous activities rather than an hint of luxury.
https://funvalley.us/