From previous measurements, including an AMON site (97), ambient levels of ammonia (NH₃) along northern Utah’s Wasatch Front are known to consistently be among the highest in the nation.  The overarching concern with NH₃ in the region is the formation of wintertime PM_2.5, which is locally-dominated by ammonium nitrate (NH₄NO₃). The Wasatch Front is considered a series non-attainment area for PM_2.5.  Several studies, most recently the 2017 Utah Winter Fine Particulate Study (UWFPS), have pointed out that although the local airsheds appear to be slightly ammonia-rich in regards to NH₄NO₃ formation. There are times, especially during extended persistent cold-pool, capping events (inversions) in which the atmosphere switches to a more ammonia-limited regime.  As such it is critical to understand NH₃ abundance and availability.  Regional emission inventories are unable to account for previously observed ambient concentrations.  Modeling attempts by local regulatory agencies have had to artificially enhance NH₃ emissions by factors as high as 4x to simulate the observed values.  Additionally, very little information is known about the location or contributions of the potential NH₃ source emissions.  Limited studies, 10 total sites, in 2016 and 2017 found ammonia wintertime concentrations ranging from 5-30 ppb with varying spatial distributions.  A study was initiated for the winter and summer of 2019 in which a dense network (40 sites) of Ogawa passive NH3 samplers were deployed from Brigham City to Mona, UT, approximately 140 miles, which include the population centers of Ogden, Salt Lake City and Provo.  The winter study took place from mid-January to mid-February and the summer study extended from mid-July to mid-August.  At present the data are still being analyzed and will be presented.  However, preliminary analysis show the average winter NH₃ concentrations (≈5-10 ppb) were lower than the average summer values (20-30 ppb), with notable difference between the Salt Lake and Utah county airshed.  During both seasons, locations near suspected “hotspots” were significantly (≈5x) higher than most of the other locations.