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.

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.

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.
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.