Invasive Species in Utah: What’s Actually Regulated

Reviewed August 2026 against the Utah Department of Agriculture and Food noxious weed list, the Utah Division of Wildlife Resources, and the Bureau of Land Management’s Utah fire program.

Try it: Run your own numbers →

Utah’s official noxious weed list currently names 54 species across five legal classes — and neither cheatgrass nor tumbleweed, the two plants most people mean when they say “invasive species in Utah,” is actually on it. Phragmites and tamarisk are (Class 3, Containment); Russian olive is (Class 4, Prohibited). Among invasive animals, the quagga mussel drives the state’s boating rules; Lake Powell is the only Utah water body with confirmed quaggas, per Utah DWR. Common carp have dominated Utah Lake for decades.

That gap between “invasive” and “legally noxious” matters if you manage land, sit on a county weed board, or just want to know what’s growing along your fence line. Below is the current class-by-class list, what each of Utah’s worst plant and animal invaders is doing to the landscape right now, and a method for checking the list yourself the next time it changes.

What Is an Invasive Species, Legally, in Utah?

“Invasive species” is an ecological description: any non-native organism whose introduction causes or is likely to cause economic or environmental harm. It is not, by itself, a legal category. The Utah Department of Agriculture and Food (UDAF) regulates a narrower list called “noxious weeds,” defined under Utah Administrative Code R68-9 and enforced county by county through the State Noxious Weed Act. A plant only lands on that list after UDAF’s Noxious Weed Committee — county weed supervisors, university extension staff, and state agency representatives — formally classifies it and hands county weed boards the authority to require landowners to control it.

That process is exactly why “what is an invasive species in Utah” and “what are some invasive species in Utah” produce different answers depending on who’s asked. A state agency answers with the legal list of 54 species. A wildlife biologist or extension agent answers with whatever is spreading fastest that season — cheatgrass, tumbleweed, quagga mussels — whether or not it’s regulated. Both answers are correct; they’re just measuring different things.

Utah’s Noxious Weed List, By Class

UDAF sorts noxious weeds into five classes based on how established a species already is and how urgently it needs to be stopped. Class 1A is a watch list for species not yet found in Utah; Class 4 is a sale ban on ornamentals that are already widespread. Based on the list published at ag.utah.gov and checked in August 2026, here is how the 54 designated species break down:

Notice what’s missing: cheatgrass (Bromus tectorum) and Russian thistle, the tumbleweed plant, appear on neither this table nor UDAF’s published list at all. That’s not an oversight — both are so thoroughly established across Utah’s 82,000 square miles that a containment or control designation would have little practical effect, and neither has been formally added by the Noxious Weed Committee. USDA’s Natural Resources Conservation Service still calls cheatgrass one of the single greatest threats to native plant communities in the Intermountain West; it’s just fought through separate wildfire and rangeland programs instead of the noxious weed statute.

Invasive Plants in Utah: The Species Doing the Most Damage

Three species do most of the visible damage to Utah’s landscape, and none of the three behaves — or is regulated — the same way.

Cheatgrass: Utah’s Wildfire Multiplier

“The big one in regards to invasive species would be cheatgrass,” Nick Howell of the Bureau of Land Management told Fox 13 Now. “The more it burns, the more it grows, but when it burns, it burns really fast.” Cheatgrass is an annual grass that cures out weeks earlier than native sagebrush, turning a landscape into continuous, flashy fuel by early summer. A study by researchers at Penn State and the University of Massachusetts-Amherst, published in Global Change Biology in December 2012, measured the effect directly: cheatgrass-invaded Great Basin rangeland now burns on an average 78-year cycle, versus 196 years for intact sagebrush-steppe — and despite covering only about 6% of the Great Basin’s land area, cheatgrass-dominated ground was implicated in 39 of the region’s 50 largest fires between 2000 and 2009, burning twice as much acreage as any other vegetation type over that decade.

The BLM’s own numbers show why this matters statewide: the agency’s Utah fire program reports the state averages more than 1,100 wildfires burning over 160,000 acres every year, and in Utah’s most active fire year since 2020, BLM-managed land still accounted for just 8% of the state’s total burned acreage — meaning most of the damage is happening on other public and private land. To slow the cycle, BLM’s Moab Field Office aerially treated roughly 13,000 acres of cheatgrass with the preemergent herbicide imazapic in the desert near Interstate 70 in November 2024, a treatment the agency expects to hold for up to five growing seasons before native seed is reintroduced, according to the BLM’s project announcement.

Because fire-return interval is the single number that best predicts whether a given parcel is in trouble, use it directly: if you know roughly how many years you plan to manage a piece of land, you can estimate how many cheatgrass-driven burn cycles it’s likely to see over that time.

Tumbleweed (Russian Thistle): Iconic, Unlisted, and Still Spreading

“Russian thistle is what tumbleweed is more commonly known as. It was probably introduced from Russia,” Utah State University Extension agriculture professor Ben Scow explained to Fox 13 Now. “Tumbleweeds were not introduced until after all of our westerns actually took place” — the plant is a 19th-century arrival, not a frontier-era native, despite its role in Western film backdrops. Salsola tragus was documented in Bonhomme County, South Dakota, in the mid-1870s, carried in as a contaminant of imported flax seed, according to the USDA-affiliated Sustainable Agriculture Research and Education (SARE) program. From that single county, it now occurs throughout the United States and southern Canada except the Deep South.

The plant’s spread mechanism is what makes it a rangeland and roadway nuisance rather than a wetland or forest problem: at maturity, the entire above-ground plant snaps off at the base and rolls with the wind, scattering seed as it goes. SARE’s research puts real numbers on that mechanism — a tumbling plant travels an average of 2,100 yards and as far as 2.5 miles before a fence line or building stops it, and even after rolling roughly a mile it still retains 26% to 51% of its original seed load. A single plant produces 5,000 to 17,000 seeds under normal competition, and up to 150,000 under ideal growing conditions. That combination — massive seed output plus long-distance wind dispersal — is why Russian thistle colonizes disturbed roadsides, fence lines, and fallow fields so readily, noxious-weed classification or not.

Phragmites: The Wetland Water Thief

Unlike cheatgrass and tumbleweed, invasive Phragmites australis is squarely on Utah’s list — Class 3, Containment — and it comes with a native look-alike that makes enforcement genuinely difficult. “There are native Phragmites that grow along the rivers naturally, and there’s also an introduced Phragmites, and they’re very difficult to tell apart,” Scow told Fox 13 Now. The introduced strain has taken over thousands of acres of Utah wetland, according to the Utah Division of Forestry, Fire and State Lands (FFSL), which manages restoration on the state’s sovereign wetlands around the Great Salt Lake and Utah Lake.

FFSL’s own figures describe why it’s so hard to remove: the reed grows 15 to 20 feet tall and can spread as much as 20 feet outward in a single growing season, it draws more than double the water of the native plants it displaces, and clearing a single established patch takes three to five years of repeated herbicide, mechanical, and controlled-burn treatment. Every gallon phragmites pulls from a wetland is a gallon that doesn’t reach downstream agriculture — the same water-budget math that applies to water management practices on irrigated farmland applies here in reverse, as an uncontrolled water cost rather than a managed one.

Invasive Trees in Utah: Russian Olive and Tamarisk

Utah’s noxious weed list includes two woody species large enough to be called trees rather than weeds. Russian olive (Elaeagnus angustifolia) sits in Class 4 — banned from retail nursery sale or propagation statewide — because it still crowds out native cottonwood and willow along riparian corridors even though it’s no longer legal to plant. Tamarisk, or saltcedar, is Class 3 (Containment) alongside phragmites; it competes for the same river-corridor water and, like phragmites, resprouts aggressively after cutting or burning unless the root crown is also treated. If a search brought you here for “invasive trees in Utah,” these two — not cheatgrass or tumbleweed, which are grasses and forbs, not trees — are the species actually named in state code.

Basket Willow: Is It Invasive in Utah?

No — at least not by Utah law. Basket willow (Salix viminalis), also called common osier, does not appear anywhere on Utah’s current noxious weed list checked against ag.utah.gov in August 2026. It’s a non-native shrub, originally from Europe, western Asia, and the Himalayas, grown commercially for basketry and biomass and classified as “exotic” to North America by the federally maintained Invasive Plant Atlas of the United States, a database run through the University of Georgia’s Center for Invasive Species and Ecosystem Health. That same database notes osier is listed on invasive-species laws or watch lists in some other states, but its distribution reports rely on incomplete, county-level EDDMapS submissions rather than a national survey — so absence from a map isn’t proof of absence on the ground, only an indication that no one has logged a sighting yet. If you’ve found what looks like basket willow growing wild in Utah, the most useful next step is reporting it through EDDMapS directly rather than relying on any single article’s snapshot of the list.

Invasive Animals in Utah

Quagga mussels and feral swine get the most attention from state wildlife officials, and they sit at opposite ends of the “how established is it” spectrum. Carp and Eurasian watermilfoil are covered in the next section.

The Utah Division of Wildlife Resources treats the quagga mussel as its top aquatic invasive species concern: the mollusk was confirmed in Lake Powell in 2012, and by the mid-2010s the National Park Service was reporting thousands of adult mussels attached to Glen Canyon Dam, canyon walls, and underwater structures. A single female can spawn up to a million microscopic veligers a year, and those veligers can attach to a boat hull within a day of exposure — which is why DWR staffs over 40 inspection and decontamination stations at reservoirs and along highways statewide, requires every boater to complete an annual mussel-awareness course, and charges motorized boat owners an annual $20 (resident) or $25 (nonresident) aquatic invasive species fee to fund the program (Utah DWR). Every other Utah reservoir, including Flaming Gorge, remains mussel-free as of DWR’s most recent update — but the agency has a rapid-response plan ready, including 24- to 72-hour access restrictions, if that changes.

Feral swine tell the opposite story. Unlike most of the American South and parts of California and Texas, Utah has never had a confirmed breeding population. “Utah does not currently have any standing herds of feral hogs,” DWR spokesperson Faith Jolley told KSL, adding that biologists have no evidence of established, reproductive groups in the state. DWR had logged 23 feral hog reports across four counties as of that 2024 reporting, mostly traced to escaped or dumped domestic pigs rather than a wild-breeding population. Utah has treated prevention as a legal matter since 2012, when the legislature made it a class B misdemeanor to release swine into the wild for hunting purposes — a law aimed squarely at stopping the kind of intentional releases that seeded feral hog populations elsewhere in the country before they can take hold here.

Aquatic invaders beyond mussels: carp and Eurasian watermilfoil

Quagga mussels get the boat inspections, but two other aquatic invaders already shape some of Utah’s best-known waters.

Common carp in Utah Lake. By the early 2000s they made up about 91% of the lake’s fish biomass, according to the June Sucker Recovery Implementation Program. Carp root up bottom plants and stir up sediment and phosphorus, which feeds algae. Since commercial removal began in 2010, more than 29 million pounds of carp have been taken out, and monitoring shows a 78% drop in carp density since 2012. The June sucker, a fish found only in Utah Lake and its tributaries, has since been downlisted from endangered to threatened.

Eurasian watermilfoil. This invasive aquatic plant forms thick mats that block sunlight and crowd out native plants. Utah DWR says it is now found in 14 Utah waterbodies, including Bear Lake, Fish Lake and Strawberry Reservoir (Utah DWR, April 2026). Fragments ride on boats, trailers and gear, so the same clean, drain and dry routine used for mussels also slows milfoil.

Neither species is a UDAF noxious weed or a quagga-style closure issue, which is why they rarely show up on short lists of invasive species in Utah.

How to Check Today’s List and Report a Sighting

Because both the noxious weed list and confirmed animal ranges change as UDAF’s committee meets and DWR logs new reports, treat every figure above as a snapshot rather than a permanent answer. Here’s the actual verification path:

• For plants: Check the current class list directly at ag.utah.gov’s noxious weed page before assuming a species is or isn’t regulated.
• For distribution: Cross-reference county-level sightings on EDDMapS, the same crowd-sourced mapping system the Invasive Plant Atlas draws from — useful for species like basket willow that aren’t on any official list yet.
• For aquatic species: Check wildlife.utah.gov’s mussel page, which DWR updates as new waterbodies are tested.
• To report a sighting: Contact your county weed supervisor for a plant, or DWR’s regional office for an animal — both are the enforcement bodies with authority to act, not just record the sighting.

Tracking Invasive Spread With Satellite Monitoring

Ground surveys and county weed-board inspections can’t cover 82,000 square miles every season, which is where remote sensing earns its keep. Farmonaut’s satellite-based crop health monitoring platform analyzes multispectral imagery to flag changes in vegetation vigor across a parcel over time — the same kind of signal that shows up when cheatgrass green-up races ahead of native sagebrush in early spring, or when phragmites expands into a wetland margin between growing seasons. It won’t replace a botanist’s identification in the field, but it can tell a landowner or county crew where to look before an infestation is visible from the road.

Explore Farmonaut’s tools directly:

Developers building their own monitoring tools can pull the same satellite and weather feeds through Farmonaut’s API and API Developer Docs.

Earn With Farmonaut: Earn 20% recurring commission with Farmonaut’s affiliate program by sharing your promo code and helping farmers save 10%. Onboard 10 Elite farmers monthly to earn a minimum of $148,000 annually—start now and grow your income!

Learn More About Farmonaut’s Affiliate Program

FAQ

1. Q: What is an invasive species in Utah, legally?
   A: “Invasive species” is an ecological term for any non-native organism that harms the environment or economy. Utah law regulates a narrower category, “noxious weeds,” defined under Utah Administrative Code R68-9 and enforced by county weed boards. A species must be formally classified by UDAF’s Noxious Weed Committee to carry that legal status.
2. Q: What are some invasive species in Utah?
   A: The most damaging are cheatgrass and Russian thistle (tumbleweed) — both widespread but not on the official noxious weed list — plus Phragmites and tamarisk (Class 3, Containment) and Russian olive (Class 4, Prohibited), which are. Invasive animals include the quagga mussel, confirmed only in Lake Powell, and common carp in Utah Lake.
3. Q: Are cheatgrass and tumbleweed on Utah’s noxious weed list?
   A: No. Despite being Utah’s most visible and destructive invasive plants — cheatgrass drives the state’s worst wildfire cycles, and tumbleweed spreads widely on disturbed roadsides and fallow ground — neither appears on UDAF’s current five-class list. They’re managed through separate rangeland and fire programs instead.
4. Q: Is basket willow invasive in Utah?
   A: Not by law. Basket willow (Salix viminalis) does not appear on Utah’s current noxious weed list. It’s non-native to North America and flagged on invasive-species watch lists in some other states, but confirmed Utah sightings aren’t documented in the national distribution databases checked for this article.
5. Q: How do I report a suspected invasive species in Utah?
   A: Report plants to your county weed supervisor, who has enforcement authority under the State Noxious Weed Act; report animals, including feral swine sightings or suspected mussel contamination, to your regional Utah Division of Wildlife Resources office. Both can also affect water management decisions on adjacent farmland, so early reporting matters beyond the immediate infestation site.