  We combine a tunable continuous-wave optical parametric oscillator and a
femtosecond Ti:Sapphire laser frequency comb to provide a phase-coherent bridge
between the visible and mid-infrared spectral ranges. As a first demonstration
of this new technique we perform a direct frequency comparison between an
iodine stabilized Nd:YAG laser at 1064 nm and an infrared methane optical
frequency standard at $3.39 \mu$m.
