The light pollution map website by Jurij Stare is a valuable tool to assess where nearby pockets of darker skies can be found. https://www.lightpollutionmap.info/help.html
A link to the mapping is on the /help page. It uses VIIRS satellite data and users can choose from a variety of overlays starting from about 2012 to recent. There is a SQM option as well. My own zenith SQM-L records correlate well with the map of my area. There are flaws with using satellite data and sometimes a high zenith reading does not necessarily indicate a good site because of the effect of bright nearby LP sources on lower elevations. Lots to explore and the app seems to be good as well.
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