  Gravitational theories do not admit gauge invariant local operators. We study
the limits under which there exists a quasi-local description for a class of
non-local gravitational observables where a sum over worldlines plays the role
of the Wilson line for gauge theory observables. We study non-local corrections
to the local description and circumstances where these corrections become
large. We find that these operators are quasi-local in flat space and AdS, but
fail to be quasi-local in de Sitter space.
