Ultra-Luminous FIR Galaxies and Sub-Millimeter Galaxies are part of an evolving population of active galaxies driven by short and intense bursts of nuclear star-formation and AGN activity. The space density of these sources peaks at z = 2-3 and extends up to z = ~6. Besides very prominent high-density tracer, the nearby ULIRGs also display powerful OH Megamaser emission. This paper considers the study of OH MM activity in ULIRGs and SMGs in the available radio windows. The extrapolation of known properties of nearby powerful ULIRGs suggests that OH emission will be observable at considerable redshifts with current and future instrumentation.