I always carry a GPS unit to mark the location of the fossils I discover, but more importantly to know exactly where I am at all times. I use an older eTrax unit from Garmin.
Every legitimate fossil hunter must know exactly where he is searching. He knows that fence lines are not always parcel lines. He must know the Longitude and Latitude of his location in proximity to State land, BLM land, a Reservation and the property line for which he has permission to search. There are no excuses. You can never say to a landowner: “I’m sorry I did now know this was your property”.
I mark my parcel maps with all of the “out of bounds” L&L coordinates. This is “must do” homework before I leave for an expedition. I found it helpful to learn my Longitude and Latitudes down to the 5th decimal place or about 3-4 feet in my search area. Personally, I always stay at least 100 feet away from the neighboring boundary just in case my published maps are not accurate.
When I start on a search hike, I first log in a Way Mark for the location of my van on my GPS. After hours of walking up and down draws and around ravines and finger washes I can lose track of the location of my van. I always orient myself to the sun and have a general idea, but after a long hike my direction instinct can be off by 60-90 degrees. I have learned to not argue with the GPS unit. Just hit the “find” button and follow the pointer back to my van.