  Reliable knowledge of parton distributions at large x is crucial for many
searches for new physics signals in the next generation of collider
experiments. Although these are generally well determined in the small and
medium x range, it has been shown that their uncertainty grows rapidly for
x>0.1. We examine the status of the distributions in light of new questions
that have been raised about "large-x" parton distributions, as well as recent
measurements which have improved the parton uncertainties.
