2024 Updates to Park County CMZ Map

The Yellowstone River naturally moves back and forth across its floodplain. This process, called channel migration, creates side channels, oxbows, fish habitat, and renews floodplain vegetation. Channel Migration, like flooding, is an important natural process that keeps the river and its habitat healthy but can also damage
structures that are built too close to the river.

The historic June 2022 flood impacted hundreds of property owners along the river. Some of the greatest impacts from the flood were from the movement or migration of the river, causing significant bank erosion and structural failures. In response, Park County received a DNRC grant to update the 2009 channel migration zone map. The 2024 Upper Yellowstone Channel Migration Zone Map is a practical tool for landowners, decision-makers, realtors, consultants, and the public to better understand this critical function of the river and prepare for and avoid future flood-related risks.