This four-year study investigated the impacts of a 2010 mast year (for red oak; Quercus rubra) and spring 2009 and 2011 prescribed fires by comparing temporal variation in tree regeneration on seven burned and unburned sites at the Mohonk Preserve in the Shawangunk Mountains of eastern New York. The overstory of all stands was dominated to varying degrees by red oak, chestnut oak (Q. montana), and red maple (Acer rubrum). Seedling density for red oak was 4267/ha in 2009 compared with 23,000/ha in 2011 as a result of the 2010 mast year. By 2012, red oak seedling density decreased to 12,714/ha, suggesting the ephemeral nature of young oak seedlings, but remained higher than pre-mast year levels. Average seedling density was 31,030/ha on the burned sites and 23,189/ha on the unburned sites and dominated by red oak followed by chestnut oak. Red oak seedling density was much higher on burned than unburned sites (mean = 19,400 versus 9578/ha, respectively), whereas chestnut oak was moderately higher on unburned sites. The results of this study suggest that while prescribed burning stimulated red oak seedling density at the Mohonk Preserve, mast year played an even larger role over the short term (which included unburned sites). Moreover, a synergistic interaction of these factors may have resulted in burned sites having the highest red oak seedling density following a mast year.