High wintertime ozone levels have been observed in the Uintah Basin, Utah, a sparsely populated rural region with intensive oil and gas operations. The reactive nitrogen budget plays an important role in tropospheric ozone formation. Measurements were taken during three field campaigns in the winters of 2012, 2013 and 2014, which experienced varying climatic conditions. Average concentrations of ozone and total reactive nitrogen were observed to be 2.5 times higher in 2013 than 2012, with 2014 an intermediate year in most respects. However, photochemically active NO_x (NO + NO₂) remained remarkably similar all three years. Nitric acid comprised roughly half of NO_z ( ≡  NO_y − NO_x) in 2013, with nighttime nitric acid formation through heterogeneous uptake of N₂O₅ contributing approximately 6 times more than daytime formation. In 2012, N₂O₅ and ClNO₂ were larger components of NO_z relative to HNO₃. The nighttime N₂O₅ lifetime between the high-ozone year 2013 and the low-ozone year 2012 is lower by a factor of 2.6, and much of this is due to higher aerosol surface area in the high-ozone year of 2013. A box-model simulation supports the importance of nighttime chemistry on the reactive nitrogen budget, showing a large sensitivity of NO_x and ozone concentrations to nighttime processes.