  We present star formation rates based on cold and ionized gas measurements of
Mrk 266 (NGC 5256), a system composed of two colliding gas-rich galaxies, each
hosting an active galactic nucleus. Using $^{12}$CO (1-0) observations with the
Combined Array for Research in Millimeter-Wave Astronomy (CARMA), we find a
total H$_2$ mass in the central region of $1.1\pm0.3\times10^{10}$ $M_\odot$
which leads to a possible future star formation rate of $25\pm10 M_\odot$
yr$^{-1}$. With the Fourier Transform Spectrograph (SITELLE) on the
Canada-France-Hawaii Telescope, we measure an integrated H$\alpha$ luminosity
and estimate a present-day star formation rate of $15\pm2 M_\odot$ yr$^{-1}$ in
the core of the system (avoiding the two active nuclei). These results confirm
that Mrk 266 is an intermediate stage merger with a relatively high recent star
formation rate and enough molecular gas to sustain it for a few hundred million
years. Inflowing gas associated with the merger may have triggered both the
starburst episode and two AGN but the two galaxy components differ: the region
around the SW nucleus appears to be more active than the NE nucleus, which
seems relatively quiet. We speculate that this difference may originate in the
properties of the interstellar medium in the two systems.
