The solar proton event (SPE) induces the changes in the neutral and ion species in Earth’s atmosphere. The highly energetic protons produce, after a series of chemical reactions, odd hydrogen (OH_x) and odd nitrogen (NO_y) during SPE. The production of odd hydrogen and odd nitrogen severely affects the mesospheric structure, chemistry and dynamics due to the presence of secondary ozone layer. This ozone density along with atomic oxygen dictates the behavior of Na density layer. The impact of SPE on mesospheric Na layer is studied over Utah (42^oN, 112^oW) during the SPE of 19 July 2012 using Na density as measured by Utah State University (USU) Na LIDAR. The changes in the mesospheric Na density layer is discussed in contrast with the atomic oxygen density and neutral temperature obtained from NRLMSISE-00 neutral model atmosphere along with the proton and x-ray fluxes measured by GOES satellites.