Dark matter is thought to make up 25% of the universe.  Dark sector particles (DSP) do not interact through the known forces but could be weakly coupled to Standard Model particles through a portal or a mediator (Dark Messenger) that could provide access to the dark matter world. Many searches for these particles at an accelerator thus far seem to face a ceiling that the sensitivity reach is greatly limited, beyond statistical effects. DAMSA (DArk Messenger Searches at an Accelerator) is an extremely short baseline experiment that proposes to break through this limit, taking advantage of high beam powers available at various accelerator facilities around the world, including the PIP-II LINAC under construction at Fermilab near Chicago, an essential element in providing the necessary high flux proton beams to the $3.5B U.S. flagship neutrino experiment, DUNE.  In this talk, I will describe the DAMSA experiment and discuss the current status and plan for DAMSA, as well as its expected sensitivity reach in the search of the Axion-Like Particle, a dark messenger, as a benchmark physics case.