Rewilding Rattlesnake Creek

Rattlesnake Creek north of Missoula lacks significant in-stream structure in the form of large wood downstream of the National Recreation Area. The natural introduction of large wood from the “derecho” wind event in July of 2024 has the potential to provide much needed aquatic habitat and stream complexity. The focus of this project is monitoring the process of “rewilding” on Rattlesnake Creek through surveys of large wood and pool habitat. The Rattlesnake has historically been subject to various forms of degradation. It was dammed in 1904, with the dam being removed 116 years later in 2020 as part of stream restoration efforts. The creek has also been heavily channelized, diverted for irrigation, and development of the riparian buffer surrounding the creek has eliminated its natural side channels. The primary goal of this project is to survey the creek post-windstorm to develop baseline data highlighting the significance of the windstorm and the contribution of fallen trees toward stream complexity and structure. Despite such degradation, large trees that fall into the creek during events like the 2024 windstorm have the potential to positively influence the streambed morphology and create critical habitat in the form of pools utilized by fish, aquatic insects, and various mammals and birds. Monitoring the benefits of large woody structure within a stream has important implications for the future as Montana and the Intermountain West continue to search for ways to adapt to changes in climate and effects of past habitat degradation.