Officials set to restore portion of Marshall Creek owned by Missoula County

Conservation workers are planning improvements for sections of Marshall Creek above the Clark Fork River to boost available habitat for a genetically pure resident trout species that live year-round in the waterway. 

Missoula County and Trout Unlimited signed an agreement Tuesday that will remove a culvert on Marshall Creek and look to preserve or widen two other culverts that would make fish passage easier on county property. 

Trout Unlimited senior project manager Rob Roberts told the Missoulian the creek has seen several restorations over the last two decades to allow for both migratory fish and westslope cutthroat trout to spawn upstream.

"Most people think it's a little piddle of a creek that flows near East Missoula, but it is actually a pretty productive fish resource," Roberts said in a phone call Tuesday.

Several years ago Montana Fish, Wildlife and Parks installed a fish ladder at the mouth of Marshall Creek by Highway 200 to allow for migratory fish to return to the waterway. 

Other work included a fish screen on an irrigation ditch to prevent the displacement of trout and replacing other culverts along Marshall Canyon Road. 

The creek still has fish passage barriers, Roberts said, including a pond on private property that prevents the upstream movement of migratory fish to the population of westslope cutthroats.

That has left the population genetically pure, and can be a resource for the larger Clark Fork River fishery because the cutthroats can move downstream in the creek during high water.  

Westslope cutthroat trout are one of Montana's state fish and have been designated as a fish of special concern because of habitat loss and hybridization with other trout species, according to FWP.

The agreement comes after the City of Missoula and Missoula County purchased the 480-acre Marshall Mountain Park in 2024, preserving public access and allowing fish managers to conduct additional restoration work. 

The Marshall Mountain Park Conceptual Master Plan from 2023 also identifies restoring fish passage and enhancing the stream channel as essential improvements.

Trout Unlimited's work plan calls for removing a culvert that was previously used for snowmaking operations when Marshall Mountain operated as a ski resort. 

Two more undersized culverts are still needed for long-term access and park maintenance, but are planned for replacement in the future as a part of the park's master plan. 

Approximately 100 feet of the stream will be restored, and once complete will benefit riparian vegetation, fish passage and westslope cutthroat trout production. 

"The goal is from the (private) pond to the rest of the watershed, about 3 miles, we want that stretch to be a prime population of westslope cutthroat trout," Roberts said. 

Missoula County agreed to provide $4,500 for materials in the project, while Trout Unlimited would maintain the disturbed site for the next 10 years. Work is planned to commence this summer.