Sometimes gas pipelines cut through properties and the gas line has easement rights but some when very old may not have today's treatment with it treated like a separate property cutting through the farm. You don't see fields getting plowed over the lines of course but pasture land is more relaxed. So, trespassing on the easement isn't really trespassing for those employees. Lots of telecommunications lines would use railway lines and buy area beside the tracks where a derailment wouldn't be likely to dredge it up or similar problems. A gas line wouldn't be along these paths of course, too much risk naturally. The photo shows light past the wall where the lumber was stacked. Might be good to ask around at neighboring properties so you can tell them you are looking for old bikes, etc and were asking neighbors in the area as well. Just don't lie that one of them told you about it if they didn't. Farming tends to run in families so it could have been a son or daughter's or the owners of the farm, presuming a farm. Just a thought. Might be more work but it could reveal more than one barn find.
Just don't educate the owners more than needed. They may go check prices on ebay and think their ship has came in from what some old bikes are listed for and they figure this gem is a was and new tires and some polish from being equal to the "finds" that show up there.
Not recommending you be dishonest or virtually steal a bike by a low low price...
They rarely are a $100 and sweat equity to to have them running and reliable and safe again. Educating them on the costs involved in points, plugs, condensor, tires, tubes, filters, carb kits, carb cleaning, cable lube or replacement, cleaning and replacing wiring ...especially if mice made a home, etc just to get started down that path can bring them into reality on the investment in just a few parts. The time involved in cleaning all contacts in the harness, etc. New keys as often they have no clue on where the keys would be. Relining or replacing a tank, grommets for sidecovers, tool kits are very pricey if you want a complete vintage kit if it doesn't have it.
A replacement title is usually easy for an owner to get in many states but it requirestime and forms to be filled out. Making that aspect easy and directing them to the web site address for those kind of things is good.
David