I’m not sure how this trespass happened; intentional, accidental, whatever but this is another reminder for folks that OnX on your phone (nor any other consumer grade software/hardware for that matter) simply aren’t accurate enough when feet of accuracy matter. I’ve experienced this myself, multiple times.
Not only have few, if any, land management entities revisited 1900’s era surveys with modern technology, but the accuracy of most consumer-grade devices just isn’t good enough. The layers in OnX are only as good as the data collected by counties, land management agencies, tax assessors, etc. Newsflash- they aren’t going out and resurveying parcels with modern tech to obtain these digital files. It’s all most likely derived from files digitized from a desktop, often by a college student or volunteer, and provided as the best data available.
This is exactly the reason I’m leary about folks emboldened by the corner crossing case in Wyoming just going forth armed with OnX and a prayer to establish precedent in other states. Equal chances it goes sideways just because, absent an actual survey marker, the tech isn’t good enough to pinpoint a corner, or a boundary, precisely for a variety of reasons.