Increasing wildfire activity over the past decade has drawn attention to the health impacts of wildfire smoke exposure.  This study builds on recent literature by examining seasonal variation in wildfire smoke plumes across ZIP codes in Oregon, leveraging these exogenous smoke shocks to estimate the causal impact of short-term exposure on hospital care utilization from 2008 to 2022.  I focus on two types of hospital encounters: inpatient admissions and emergency department (ED) visits.  After establishing a strong link between wildfire smoke and elevated levels of particulate matter less than 2.5 micrometers in diameter PM2.5 I find robust evidence that smoke exposure significantly increases both hospital admissions and ED visits.  I further estimate the costs of avoided illnesses under a hypothetical reduction in smoke levels during 2020–2022. Had smoke exposure been reduced to lower levels, an estimated 208 circulatory and 318 respiratory hospital admissions could have been avoided, saving approximately $3.5 million (2017 USD) and $5.3 million, respectively.  For ED visits, this reduction would correspond to 376 fewer circulatory and 1,689 fewer respiratory visits, valued at approximately $0.5 million and $1.6 million in avoided costs.