  We present preliminary results for the heavy-light leptonic decay constants
in the presence of three light dynamical flavors. We generate dynamical
configurations with improved staggered and gauge actions and analyze them for
heavy-light physics with tadpole improved clover valence quarks. When the scale
is set by $m_\rho$, we find an increase of approximately 23% in $f_B$ with
three dynamical flavors over the quenched case. Discretization errors appear to
be small (of order 3% or less) in the quenched case but have not yet been
measured in the dynamical case.
