California Golden Mussel Rules for Boaters

**Golden mussels are a new invasive species in California, and every boater is now asked to Clean, Drain and Dry after every outing. Motorized boats used in fresh water also need a $16 Mussel Fee sticker from DMV. Beyond that, the rules differ lake by lake, so check each lake's current requirements before you tow.**

What are golden mussels?

The golden mussel (*Limnoperna fortunei*) is a non-native freshwater and brackish-water bivalve, about three-quarters of an inch to 2 inches long, light to dark yellowish-brown to brown.

Timeline

• **October 2024:** golden mussels were first detected in North America at the Port of Stockton in the Sacramento-San Joaquin Delta.
• **April 2025:** the Department of Fish and Wildlife announced a Golden Mussel Response Framework, $1 million in grants to boating facility operators, inspection and decontamination programs, and red quarantine bands for inspected boats.
• **After the Delta:** golden mussels were later found at O'Neill Forebay in Merced County, part of the State Water Project.
• **October 2025:** the Department of Water Resources reported golden mussels at San Luis Reservoir during routine testing, with mandatory inspections of all vessels leaving San Luis Reservoir.

Why they matter to boaters

Golden mussels filter-feed and change ecosystems. They clog pipelines, screens and filters. On boats they foul hulls and motors, and they can clog engine intakes and cooling lines. They tolerate a wide range of conditions and spread easily, especially on boats moved from one lake to another.

Clean, Drain, Dry in detail

State agencies recommend doing this after every outing, and before launching somewhere new:

• **Clean:** remove plants, mud and animal material from the boat, trailer and equipment before you leave the water.
• **Drain:** drain ballast, bilge, live wells and any other place that holds water. Never drain back into the waterway.
• **Dry:** let equipment dry before launching into another waterbody. Waiting periods vary, so ask the lake owner what its inspection criteria are.

The $16 Mussel Fee sticker

DMV requires owners of motorized recreational vessels used in fresh water to display a current Mussel Fee sticker, unless the vessel is used only in marine waters or is exempt by law. As of October 2026, per DMV:

• The fee is **$16**, and it expires when your vessel registration renewal sticker does.
• Request it online with DMV and have your CF number ready. Card payments add a 1.95% processing fee; direct bank payments have none.
• Since 2021 it is a **separate transaction** from registration, and the sticker is mailed separately.
• Affix it to the hull on either side of the registration sticker, on both the starboard and port sides. DMV says failing to do so may result in a citation.

The sticker is a state fee. It is not an inspection pass, and it does not replace a lake's own inspection or quarantine rules. Confirm current details on the DMV Mussel Fee page.

Inspections, quarantine bands and decontamination

Inspection programs are run by the water agency or park that manages each lake, not by one statewide system. Depending on the lake, a boat may be quarantined for a set period or decontaminated. Red quarantine bands are applied to inspected boats under the state's response framework. For contacts at individual boating facilities, see the DBW inspections page.

Rules differ lake by lake

These examples come from Dockya's lake listings and show how much the rules vary. They change, so check the lake's own page and the managing agency before you go.

• **Lake Oroville:** DWR discontinued its mussel inspection, decontamination and seal program on April 29, 2026, and asks boaters to keep doing Clean, Drain and Dry.
• **Shasta Lake and Trinity Lake:** under Forest Order 14-25-29 (December 4, 2025 to December 4, 2027), possessing or transporting golden, zebra or quagga mussels below the high-water mark or on ramps at Shasta Lake is prohibited, with fines up to $5,000 for individuals. At Trinity Lake, boaters must obtain and display an Invasive Mussel-Free Certification before launching.
• **Folsom Lake:** trailered or motorized vessels must be inspected, then quarantined for 30 days under a seal or decontaminated for a green seal (program effective April 14, 2025).
• **Lake Del Valle:** in September 2026 the East Bay Regional Park District reported golden mussels and applied a 30-day quarantine to boats launching there, unless they launch only at Del Valle and keep their band or pass intact.
• **Lake Tahoe:** every motorized boat needs an aquatic invasive species inspection, or an intact seal, before launching. Book ahead.
• **Pyramid Lake:** all watercraft must pass a mussel inspection before launch, and exit inspections have run since quagga mussels were found in 2016. DWR confirmed golden mussels at Pyramid and Silverwood lakes in September 2025.
• **Silverwood Lake:** State Parks says incoming inspections were discontinued because golden mussels were found, and asks boaters to pull drain plugs before leaving. Other park pages still mention seals, so call before you go.
• **New Bullards Bar Reservoir:** all motorized watercraft must be screened before launching, and a boat can be denied launch for visible mussels, excessive standing water or recent use in infested waters.
• **Lake Casitas:** every vessel must pass inspection with a 35-day quarantine, and boats that fail may not be reinspected for at least seven days.

Before you tow to a new lake

• Check the lake's official page for current inspection, quarantine and ramp rules. They can change quickly.
• Confirm your registration is current and your Mussel Fee sticker is on both sides of the hull.
• Clean mud, plants and animals off the boat, trailer, anchor and gear.
• Drain the bilge, live wells, engine and any other water-holding spaces. Pull the drain plug.
• Dry everything thoroughly, and ask the lake how long it expects.
• Book inspections where required, and arrive during inspection hours.

Report a sighting

If you think you have found a golden mussel, report it to the Department of Fish and Wildlife's Invasive Species Program at Invasives@wildlife.ca.gov or (866) 440-9530. More information is on the CDFW golden mussel page.

This guide is general information, not legal advice; check the linked official pages.