  A re-analysis of the NMC and SLAC data leads to a great improvement in our
knowledge of the valence d and u parton distribution functions at high x.
Standard parton distributions with our modifications are in good agreement with
QCD predictions for d/u at x=1, and with the CDHSW nu p and nubar p data, the
HERA charged current cross section data, the collider high-P_t jet data, and
the CDF W asymmetry data. With the inclusion of target mass and higher twist
corrections, the modified PDF's also describe all DIS data up to x = 0.98 and
down to Q^2 = 1 GeV^2.
