Found a few things from a news video segment for KULR
Wake Up Montana! A company called Xanterra Travel Collection owns the park.
Here is a link to their site and the latest info - but no map...
https://www.yellowstonenationalparkl...ridge-rv-park/
You might try emailing this guy, explain what you need and see if he responds.
Rick Hoeninghausen - Marketing and Sales Directot for Xanterra
rhoeninghausen@xanterra.com