What happens to an easement if the property it crosses gets subdivided among multiple new owners?

The easement continues to burden whichever portion, or portions, of the land it physically crosses, regardless of how the servient property is later subdivided among different new owners. Subdividing the burdened land doesn't erase the easement; each new owner of a lot the easement actually runs through takes that lot subject to it, the same way the original owner did.

The flip side is that new owners of portions the easement doesn't physically touch aren't affected by it at all. Subdivision effectively narrows which specific new owner, or owners, actually bears the burden down to whoever ends up owning the land the easement crosses, rather than spreading a diluted version of the obligation across every resulting lot. If the easement's exact path crosses a boundary created by the subdivision itself, more than one of the new lots could end up sharing the burden.

Anyone buying a newly subdivided lot should specifically check, through a title search and survey, whether an existing easement crosses their particular lot, rather than assuming that just because the original larger parcel had one, it now applies loosely across all the resulting smaller lots.