Intertidal mussels, like the California mussel (Mytilus californianus), routinely experience fluctuations in their natural environment, including temperature, aerial exposure, and food availability. The intertidal zone is inherently stressful, thus successful colonization of this habitat necessitates high phenotypic plasticity to multiple stressors. Recent research has shown that previous food ration and thermal history significantly influence the survival and physiology of these mussels during extreme heat events, yet the molecular mechanisms that contribute to increase thermal resilience are not well understood. As part of a broader study, we used a shotgun proteomics approach (LC-MS/MS) to investigate molecular-level variation in gill tissue of M. californianus acclimated to combinations of high or low algal rations and high or low emersion temperatures in environmental chambers that mimic tidal cycles. To account for natural rhythms, samples were collected every 3 h for 48 h, following the 3 wk acclimation period. We employed label-free quantification methods to assess significant changes in protein abundance among the acclimation groups. Overall, we were able to identify 350 proteins and quantify 175 proteins within the 320 samples analyzed. Preliminary analyses of our initial time points indicate that acclimation temperature may have more of an effect on protein abundance than algal ration, including significant changes in small heat shock protein 24 and ATP synthase. We expect to see interesting patterns emerge in protein abundance over time that correspond to the low tide cycles (i.e., emersion temperatures), feeding events, and recovery from aerial exposure.