For this abstract, we have selected an impact location, consistent with the PDC2021 initial scenario , in the San Juan Mountains, in southwestern Colorado. This is a low-density population area but is part of the watershed system within the Colorado River basin, a major source for water and power for the southwestern United States. Several large cities and major airports are potentially downwind from this area. For the PDC2021 scenario , a 120-meter impactor is the median expected size. We chose impactor sizes ranging from 42-meters to 600-meters, which covers the 0.1% smallest to largest cases.