Pocket gophers (Thomomys spp.) are burrowing rodents that spend nearly their entire lives underground, making them among the most cryptic and frustrating pest species in Montana. Named for the fur-lined external cheek pouches they use to carry food, pocket gophers are solitary and fiercely territorial — each animal maintains its own burrow system, which it defends aggressively against others of its species.
In Montana, pocket gophers inhabit a wide range of soil types across valleys, hillsides, meadows, gardens, lawns, pastures, and roadsides. Their underground activity is relentless — a single animal can excavate hundreds of pounds of soil per month and maintain a burrow network covering hundreds of square feet. Unlike ground squirrels (which leave open burrow entrances), pocket gophers seal their tunnels from the inside and are most evident through the fan-shaped mounds of loose soil they push to the surface.
The damage they cause to lawns, gardens, crops, orchards, and underground infrastructure — irrigation lines, electrical conduit, drainage systems, and buried cables — makes them a significant and costly pest for Montana homeowners, landscapers, golf courses, and agricultural operations.
Size
6–10 inches; 3–8 oz
Color
Brown to gray-brown
Active Season
Year-round (active underground in winter)
Risk Level
Medium–High (lawn/garden/infrastructure damage)
Habitat
Deep loamy to sandy soils; lawns, pastures, gardens
Behavior
Solitary; spends nearly all time underground
SIGNS OF INFESTATION
How to Identify Pocket Gopher Activity
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Fan-shaped soil mounds — The definitive sign: crescent or horseshoe-shaped mounds of loose, fine soil pushed to the surface with a plugged opening on one side. Distinct from the volcano-shaped mounds of moles.
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Freshly disturbed soil — New mounds appearing overnight or after rain indicate active burrowing.
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Damaged plant roots — Plants wilting or dying without apparent above-ground cause — gophers sever roots from below, causing sudden plant death.
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Severed irrigation lines — Drip irrigation tubing pulled underground or chewed through by foraging gophers.
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Subsidence in lawns — Soft or hollow-feeling areas where shallow tunnels have collapsed.
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Chewed buried cables — Low-voltage landscape lighting, irrigation control wire, or buried electrical cable chewed through underground.
HEALTH RISKS
Pocket gophers are rarely a direct health risk to humans as they are almost never above ground. Their burrows can harbor fleas that may carry diseases, and soil disturbed during cleanup can contain leptospirosis bacteria in some areas. Standard precautions (gloves and hand washing) are sufficient for most homeowner interactions.
PROPERTY DAMAGE
Pocket gopher damage to lawns can be extensive — a single animal can produce 70 or more mounds per year, each requiring filling and re-seeding. Garden and orchard damage from root severing can kill mature shrubs and young trees outright. Chewed irrigation lines are a very common and costly problem in Montana's irrigated landscapes — repair costs for a single season of gopher damage to drip systems can run into the hundreds of dollars. Undermined embankments, ditch banks, and roadside slopes are also a documented problem in areas with heavy gopher pressure.
