The Upper St. Mary Watershed

Tucked away in the southwest corner of Alberta, the St. Mary River is home to a variety of unique species in the province. This watershed is home to three threatened fish, Bull Trout, Westslope Cutthroat Trout, and a small, unassuming fish, hiding between rocks in the streambeds – the Rocky Mountain Sculpin.  These species are threatened in part due to habitat degradation, often cumulative from a range of human impacts. In the upper St. Mary, decades of off-highway vehicle (OHV) use and cattle grazing have compacted soils, funneled sediment into creeks and prevented re-growth of plants along stream banks. Over the past three years, Freshwater Conservation Canada has partnered with leaseholders in the Pole Haven Grazing Lease (PHGL), private landowners in the broader watershed, and Cows and Fish to recover stream banks, install grazing best management practices, and combat future degradation. We have also worked with the Alberta Off-Highway Vehicle Association to install needed off-highway vehicle (OHV) crossings. The St. Mary is one of only three river systems in Canada where the Rocky Mountain Sculpin is found.  Because of their limited distribution and relatively low numbers, every meter of habitat matters for protecting this fish in Alberta.

Harnessing the Power of Plants!

Did you know? Willows and poplars can grow from just a branch cutting! That’s because these two species have evolved to take advantage of damage from beavers and seasonal flooding to colonize new areas. In nature, these broken off branches are carried by the river to new banks and gravel bars, become partially buried by stream sediment, and grow new roots and shoots using the energy stored in the wood. This year, we took advantage of this cool evolutionary process, and planted >550 willow and poplar stakes to revegetate degraded riparian areas, and help stabilize eroding banks.

A Rare Winter Field Trip

FCC staff emerged from their winter hibernation early in 2026 to complete some trail and riparian rehabilitation at the PHGL. This work built on habitat and trail assessment work completed in 2023 and 2024 and focused on reclaiming unused and redundant trail segments used by the area leaseholders to reduce sediment delivery into Lee Creek and Tough Creek. We worked with Leaf Ninjas to complete this work, who took the chilly conditions at site in stride.

While many of the reclaimed trails and stream crossings currently receive low or no use, they still degrade critical habitat for the aquatic residents of Lee and Tough Creek. That’s because the compacted soils on the trails cannot hold on to water, and instead act as a raceway for water moving down the trail surface. Water does not encounter much friction on the relatively smooth surface of the compacted trails, and picks up speed, just like a ball rolling down a hill. The fast-moving water is powerful, able to carry loose soil particles in its flow, and is pulled down by gravity towards the stream, where the silty water is deposited. Rocky Mountain Sculpin spend most of their lives hiding in the spaces between loose gravels and boulders, and when the fine silt particles delivered by the trail enter a creek, they fill in these hiding spaces, leaving the sculpin with nowhere to hide from predators.

To address this issue, approximately 800m of compacted trail surfaces were decompacted using a small excavator. This creates loose, fluffy soils that hold onto water instead of shedding it, reducing sediment delivery into the creek, and recharging groundwater aquifers. The loose soils are also the perfect growing medium for new plants, promoting rapid revegetation of these disturbed surfaces. To help speed up the revegetation process, FCC also distributed woody debris over the reclamation area, and spread native seeds on the freshly decompacted soils.

In addition to soil decompaction and native seed distribution, FCC also installed one stream crossing structure over a needed stream crossing, removed a damaged culvert that was creating issues with water ponding upstream, and worked with the leaseholders at the PHGL to expand a seasonal grazing exclusion fence on Lee Creek over degraded riparian area.

Still More to Come

FCC will continue to monitor and maintain the 2026 rehabilitation sites for years to come, and will continue working in the area to restore degraded sculpin and trout habitat wherever we can! Do you live in in the upper St. Mary watershed, and are wondering how you can help your fishy friends? Reach out to us at info@freshwatercanada.org!

2025-2026 Acknowledgements

This work was supported by funding from Fisheries and Oceans Canada’s Habitat Stewardship Program, Alberta Conservation Association’s Conservation Community and Education Grant, and TC Energy through Environment and Climate Change Canada’s Conservation Exchange Pilot. Thank you to our partners at the Pole Haven Grazing Association for their input with rehabilitation planning, a private landowner along Lee Creek who requested our assistance with an eroding bank, and our willow staking volunteers!