Plains Sucker

Habitat Distribution

• Native to Canada; found in two separate drainage systems — the Missouri Basin (Milk River watershed in Alberta and Saskatchewan) and the Saskatchewan–Nelson Basin.
• Restricted to cool, clear, fast-flowing prairie and foothill streams east of the Rocky Mountains; not found in lakes or slow, warm lowland rivers.
• Missouri Basin populations in Alberta and Saskatchewan are assessed as Threatened by COSEWIC; the Saskatchewan–Nelson population is assessed as Special Concern.
• Habitat has become increasingly fragmented due to agricultural water management, flow augmentation, and sedimentation from eroding banks.

Key Locations

• Milk River watershed, southern Alberta and Saskatchewan — core habitat for the Threatened Missouri Basin population.
• Frenchman River, Saskatchewan — a Saskatchewan–Nelson Basin site with a genetically distinct, isolated population showing reduced diversity.
• Prairie tributaries of the Saskatchewan–Nelson drainage in Saskatchewan — the more connected and currently more resilient of the two Canadian population groups.

Specific Spots

• Riffles and runs with clean gravel or cobble substrate — this is where they feed and spawn, and where you're most likely to encounter them incidentally.
• Current breaks behind larger rocks or woody debris in small to mid-sized streams, where they shelter from strong flow.
• Shallow, well-oxygenated sections of stream; they avoid slow, silty pools and warm, turbid water.