Bear Lake Invasive Plants

Current treatment notices

Invasive plant treatment notices will be posted here.

Invasive, submerged aquatic plant species that threaten Bear Lake

Eurasian watermilfoil

Eurasian watermilfoil is a non-native, invasive plant species that severely impacts navigation, recreation, fish habitat, and water quality. Eurasian watermilfoil was first detected in Bear Lake in 2019; it was listed as a noxious weed in Utah in 2024. At Bear Lake, this species is found growing in the water around the lake in areas where light can penetrate to the bottom. This species spreads primarily through plant fragments that break off, move throughout the lake, and root in another location. In marinas, this species can grow to the surface, blocking lake access for boats, jet skis, swimmers, and other recreationalists. Eurasian watermilfoil is an important plant species to manage— Forestry, Fire and State Lands monitors and treats this species annually.
Feathery, green Eurasian watermilfoil laid flat to measure (about 18 cm). There are thin stems and leaves arranged in whorls, forming a dense mat.

Curly-leaf pondweed

Curly-leaf pondweed is a non-native, invasive plant species that severely impacts navigation, recreation, fish habitat, and water quality. Populations of this species have been detected in Bear Lake marinas. Curly-leaf pondweed grows quickly in Bear Lake in the spring and early summer and produces turions, or winter buds, in mid-summer. These buds can sprout in the fall and overwinter, giving this plant a head start over native plant species come spring. This species also spreads through plant fragmentation. Forestry, Fire and State Lands monitors and treats this species every year.
A photo of curly-leaf pondweed, a submerged aquatic plant, showing its characteristic wavy, lasagna-like leaves with serrated edges. The leaves are olive-green to reddish-brown and attached directly to the stem.

Species not yet detected at Bear Lake— parrot feather and hydrilla

Other invasive submerged aquatic plant species that have not yet been documented in Bear Lake include hydrilla and parrot feather. Parrot feather has been documented in neighboring Cache County, UT and hydrilla has been documented in southern Idaho. Like Eurasian watermilfoil and curly-leaf pondweed, these species can have strong negative effects on our society and the environment. The best way to prevent these species from spreading into Bear Lake is to practice Clean, Drain, Dry.
Parrot feather, an aquatic plant with vibrant green, feathery leaves, visible above and below the water surface.

How you can prevent the spread of invasive species: Clean, Drain, Dry

Invasive plants can be accidentally transported when people go fishing and boating. Cleaning off all aquatic plant fragments, seeds, animals, and mud from all watercraft and equipment will prevent unwanted hitchhikers from being introduced into another lake or area.

Learn more about how you can prevent the spread of aquatic invasive species.

Invasive vegetation wrapped around boat propeller.
Invasive vegetation caught on boat trailer.

How Forestry, Fire and State Lands manages invasive plants at Bear Lake

Invasive plant species threaten ecosystems, fish and wildlife habitat, recreation, agriculture, and economies. Managing the invasive plant populations that grow in and around Bear Lake is one aspect of Forestry, Fire and State Lands’ land management. Controlling invasive plant species in Bear Lake wetlands requires monitoring and adapting to the lake levels and plant populations that are present each growing season.

Lakeshore wetlands are commonly invaded by both terrestrial and wetland weeds. Bear Lake is no exception. Invasive terrestrial plant species that tolerate dry conditions (for example, Dyer’s woad) and species that thrive in wet conditions (for example, invasive Phragmites and purple loosestrife) are commonly found. Some invasive plant species even occupy the water column in shallow areas at Bear Lake. Both Eurasian watermilfoil and curly-leaf pondweed are invasive, submerged aquatic plant species that have been found growing in the marinas and in the open waters up to 30 ft deep.

Standing in a boat holding up invasive vegetation.
At Bear Lake, invasive plant species threaten navigation, recreation, fish and wildlife habitat, water quality, and local economies. Forestry, Fire and State Lands monitors invasive plant species and works to prevent their spread. Forestry, Fire and State Lands’ staff, contractors, and collaborators control invasive plants at Bear Lake using various methods (e.g., chemical, mechanical/physical, cultural, biological, prevention) that are tailored to the plant species’ life cycles and characteristics.
Monitoring Invasive vegetation on the shore of Bear Lake.

Invasive plant species of focus at Bear Lake

Here are some of the plant species at Bear Lake that Forestry, Fire and State Lands manages:

  • black henbane
  • curly-leaf pondweed
  • Dalmatian toadflax
  • Dyer’s woad
  • Eurasian watermilfoil
  • houndstongue
  • knapweed (spotted, Russian)
  • purple loosestrife
  • Phragmites
  • Russian olive
  • tamarisk
  • thistles (Scotch, Canada, musk, bull)
  • whitetop (hoary cress)
  • weedy species (e.g., teasel, burdock, mullein)
  • other state-listed noxious weeds
Invasive vegetation on shores of Bear Lake.Monitoring vegetation from Bear Lake on a dock.

Contact

Rae Robinson, Sovereign Lands Restoration Coordinator, at raerobinson@utah.gov