  We present a measurement of the $\ttbar$ production cross section in $\ppbar$
collisions at $\sqrt{s}=1.96$ TeV using events containing a high transverse
momentum electron or muon, three or more jets, and missing transverse energy.
Events consistent with $\ttbar$ decay are found by identifying jets containing
candidate heavy-flavor semileptonic decays to muons. The measurement uses a CDF
Run II data sample corresponding to $2 \mathrm{fb^{-1}}$ of integrated
luminosity. Based on 248 candidate events with three or more jets and an
expected background of $79.5\pm5.3$ events, we measure a production cross
section of $9.1\pm 1.6 \mathrm{pb}$.
