River Design Group completed a wetland delineation report and functional wetland assessment at Lost Trail National Wildlife Refuge, near Marion, Montana. Encompassing 9,225 acres in Pleasant Valley, the Refuge contains wetlands, lush riparian corridors, uplands dominated by prairie and tame grasses, and temperate forests. Pleasant Valley Creek runs through the Refuge from the north to the southwest. Land use practices prior to Refuge establishment resulted in wetland draining, creek straightening and channelization, and railroad and road establishment directly through the historical wetlands.
The wetland assessment included evaluation of all area that could be impacted with the implementation of the Pleasant Valley Road Relocation and Stream and Wetland Restoration Project. The restoration project included moving Pleasant Valley Road from its valley bottom location which bisected wetlands, to upland areas, as well as restoration of Pleasant Valley Creek and natural groundwater hydrology. 1,018 acres of the Refuge were evaluated, and a total of 107 acres of wetlands and Waters of the U.S. were delineated and mapped, including Palustrine Emergent, Scrub-Shrub, Forested, Open Water, and Riverine Waters of the U.S. A detailed wetland impact analysis defined the amount and type of impacts proposed with restoration work to existing wetlands at the Refuge.