I don't know about all prepaid phones but Android and iPhone smart phones now all have integral GPS capability. Google Maps and National Forest Service interactive maps can show you where you are without an internet or phone connection. I have a demo Kyocera that my brother gave me to fly a toy drone. It's never had a phone plan but it tells me everywhere I am. I wish I'd have had that easy location access when I was doing field research back in the 80s and 90s but civilian GPS units were way too expensive for me to afford back then. I determined my location the old fashioned way, with map and compass and Geodetic Survey markers.