The CDF Collaboration has analyzed ~200 pb-1 of Tevatron Run II
data taken with the CDF II detector between February 2002 and September 2003
to measure the W boson mass. With a sample of 63964 W --> e mu decays and
51128 W --> mu nu decays, we measure M_W = 80413 +/- 34(stat) +/- 34(syst)
MeV/c2. The total measurement uncertainty of 48 MeV/c2 makes this result
the most precise single measurement of the W boson mass to date.