Background: Following the onset of the COVID-19 pandemic in March 2020, there was a drastic reduction in elective procedures, including screening mammograms. This was accompanied by a precipitous drop in the number of breast cancer diagnoses in 2020 compared with other years. The first aim of this study was to determine the extent of reduced mammogram screening during the first year of the COVID-19 pandemic. Secondary aims of this study were to determine the effect of reduced screening on breast cancer staging at initial diagnosis and to determine if there was a significant difference in screening patterns between rural and urban settings. Methods: This was a retrospective study. Mammogram data and cancer diagnosis data was collected from the time periods of March 2019 - Feb 2020 (Year 1) and March 2020 - Feb 2021 (Year 2). The patient data was selected from the Duluth/Essentia Cancer registry and through the Essentia Breast Imaging registry. Patient records were reviewed for cancer diagnosis and stage. Data on the number of mammograms performed was collected from Essentia sites across northern Minnesota that offer mammography services, including Duluth First Street, West Duluth, Virginia, and International Falls. Results: The demographics of patients diagnosed with breast cancer were similar between the two years. The total number of screening mammograms between March – May 2019 was 3,124. The total from March – May 2020 was 1,016, which is a reduction in the number of screenings of 2,108. Comparing June 2019 – Feb 2020, the total was 10,102, as compared to 10,459 in June 2020- Feb 2021, a total of 357 higher. This translates to a reduction of 1,751 screenings in Year 2 compared with Year 1. Between Year 1 and Year 2, we saw an increase in the proportion of stage III/IV breast cancers diagnosed, from 9.6% in Year 1 to 16.9% in Year 2, accompanied by a decrease in stage I/II cancers from 90.4% to 83.1% (p = 0.06). The total diagnoses between Year 1 and Year 2 also decreased from 211 to 185. We saw a significant decrease in the proportion and number of residents that were diagnosed via screening mammograms from urban settings during COVID, while rural patients had a significant increase in proportion and number. Conclusions: There was a remarkable reduction in the total number of screening mammograms and breast cancers diagnosed during the first year of the COVID-19 pandemic compared with the year prior. Patients were lost to screening, and potential diagnoses were not made. Those that did come in were more likely to present with an advanced stage cancer. Patients from rural settings were more likely than those from urban settings to be diagnosed via screening mammogram during COVID, but more investigation should be done to determine screening patterns among these populations.Providers should emphasize the importance of screening mammograms with patients and should be attentive to higher-staged cancers due to missed screenings.