Prevention is the only solution! Watercraft inspection is MANDATORY.
New ordinances in Mono and Inyo Counties require inspections before launching any trailered watercraft, including boats and jet skis, into any body of water.
Trailered watercraft must stop at a Watercraft Inspection & Decontamination (WID) station and receive an Eastern Sierra mussel sticker before launching.
Launching without an inspection may result in fines, misdemeanor charges, and/or boat impoundment.
Resident watercraft (Mono or Inyo County): Inspected once per year before the first launch of the season.
Visiting watercraft: Inspected when entering Mono or Inyo County before launching.
Watercraft inspected in Inyo County or Mono County: That inspection is valid in Mono or Inyo County for the same month.
Any boat that launches outside Mono or Inyo County: Must be inspected again before launching locally.
WID Stations
Locations, dates, and hours are subject to change! Please check this website again before you visit.
Bridgeport
TBD if this location can handle decontamination of wakeboard boats. Crowley Lake and Bishop can decontaminate wakeboard boats.
Location:
Hours: To be confirmed, but expected 7-days per week from 6:30 AM to 3:00 PM opening the week of April 20 through October.
Crowley Lake
Crowley Lake will offer inspection and decontamination for wakeboard boats ONLY.
Otherwise, inspections will be for watercraft accessing Crowley Lake.
Bishop
- Stop here before driving north.
- Wakeboard boats can be inspected and decontaminated at this WID station.
Location: Von’s parking lot – 1190 N. Main Street, Bishop, CA 93514
This location available Opening Weekend only
Wednesday, April 22: 7:00 AM to 3:00 PM
Thursday, April 23: 7:00 AM to 3:00 PM
Friday, April 24: 6:30 AM to 10:00 PM
Saturday, April 25: 7:00 AM to 3:00 PM
Sunday, April 26: 7:00 AM to 3:00 PM
Location: 620 South Main Street (US 395), Bishop, CA 93514
Opening: Monday, April 27
Hours: 7-days per week from 6:30 AM to 3:00 PM
Expected April through October
Diaz & Klondike Lakes
These lakes operate their own inspection programs. Inspections at Diaz and Klondike are only for watercraft launching at those locations.
Once inspected, your mussel sticker is valid for launching throughout Mono and Inyo Counties. Inspections completed at Bridgeport, Crowley Lake, or Bishop are also accepted at Diaz and Klondike.
This reciprocity is limited to Mono and Inyo Counties.
Golden Mussel FAQ
Golden mussels are an invasive freshwater species not yet detected in the Eastern Sierra — and keeping them out is critical.
They spread primarily by hitchhiking on boats, trailers, and gear that move between lakes and rivers. Once they are here, they cannot be removed.
Why Are They Such a Serious Threat?
Golden mussels:
- Attach to almost anything — docks, rocks, boats, motors, pipes, aquatic plants, even muddy lake bottoms
- Survive in a wide range of water temperatures and chemistry, including low-calcium waters like many Eastern Sierra lakes
- Can live outside of water for periods of time
- Reproduce rapidly, spawning multiple times per year and producing thousands of microscopic larvae (called veligers) that are nearly impossible to detect
Unlike quagga or zebra mussels, golden mussels are especially capable of surviving in Eastern Sierra conditions.
Why Should We Care in the Eastern Sierra?
If introduced to the Eastern Sierra, golden mussels can:
- Permanently damage lake and stream ecosystems
- Deplete plankton that fish depend on for food
- Threaten recreational fishing, boating, and tourism
- Clog docks, motors, water delivery systems and pipes
- Increase water and power costs due to expensive maintenance
In October 2024, golden mussels were detected in the Port of Stockton. In less than one year, they spread more than 250 miles south.
Our lakes and rivers are highly interconnected. An introduction in one location could spread quickly across the region. Prevention is the only solution.
How much does it cost to get an Eastern Sierra Mussel Sticker?
The entire process – inspection, decontamination, and the stickers (watercraft and trailer) – is free!
How long are Eastern Sierra Mussel Stickers valid?
→ Resident watercraft (Mono or Inyo County): Inspected once per year before the first launch of the season.
→ Visiting watercraft : Inspected when entering Mono or Inyo County before launching.
→ Watercraft inspected in Inyo County: That inspection is valid in Mono County for the same month. This reciprocity is limited to Mono and Inyo Counties.
→ Watercraft inspected in Mono County: That inspection is valid in Inyo County for the same month. This reciprocity is limited to Mono and Inyo Counties.
→ Any watercraft that launches outside Mono or Inyo County: Must be inspected again before launching locally.
There is no charge for inspection, decontamination (if necessary), or the stickers (one for watercraft, one for trailer).
What watercraft or vessels need an inspection?
All trailered watercraft must be inspected before launching in Mono or Inyo County waters. This includes:
- Motorboats
- Jet skis
- Any watercraft transported on a trailer
- Float planes
From the ordinance: “Water vessel” means any trailered watercraft, or jet ski, or float plane capable of being launched into a water body within the County of Mono except as specifically exempted herein. Canoes, kayaks, car- top boats, float tubes, rafts, wind surfers/boards, boogey boards, nonmotorized paddle boats, and nonmotorized sail boats that are eight (8) feet or less in length are not considered water vessels for purposes of this article and are thereby exempt from the provisions herein.
Do kayaks, paddleboards, or other non-trailered watercraft need an inspection?
Canoes, kayaks, paddleboards, float tubes, and rafts are generally not required to be inspected. However, all gear (including waders) must follow Clean, Drain, Dry practices, and inspections or decontamination are encouraged if you have any concerns.
Before entering any waterbody:
- Clean all boats and gear of visible plants and mud
- Drain all water from equipment
- Dry everything thoroughly
These steps help prevent the spread of invasive species and protect Eastern Sierra waters.
From the ordinance: “Water vessel” means any trailered watercraft, or jet ski, or float plane capable of being launched into a water body within the County of Mono except as specifically exempted herein. Canoes, kayaks, car- top boats, float tubes, rafts, wind surfers/boards, boogey boards, nonmotorized paddle boats, and nonmotorized sail boats that are eight (8) feet or less in length are not considered water vessels for purposes of this article and are thereby exempt from the provisions herein.
Do visiting boats need a new inspection each month?
Yes. Visiting boats must have a valid sticker for the current month. If your sticker expires, you’ll need a new inspection and sticker to continue launching—even if you haven’t left the area.
What is Mono County doing to address watercraft inspections locally?
Mono County and regional partners are actively working to expand watercraft inspection options throughout the Eastern Sierra.
This includes developing an attestation process and working directly with local resorts and marinas to address watercraft that remain in the area, such as rentals and other boats that do not travel outside of Mono or Inyo Counties.
We are also working to secure funding, staffing, and logistics to support pop-up inspection sites in multiple communities, making it easier for residents and visitors to access inspection services.
This is a rapidly evolving effort, and we appreciate your patience as we continue to build and refine these programs to best protect our local waters.
What happens during a watercraft inspection?
An authorized inspector will:
- Ask a few questions about where your boat has recently been used
- Inspect your boat and trailer for water, mud, or invasive species
This includes checking areas like motors, bilge, livewells, ballast tanks, and any place water can collect.
What are inspectors looking for?
Inspectors are checking to make sure your boat is:
- Clean (no plants, mud, or debris)
- Drained (no standing water)
- Dry (no moisture that could carry invasive species)
They are also assessing whether your boat has recently been in higher-risk waters.
What happens if my boat passes inspection?
If your boat is clean, drained, and dry, and does not pose a risk, you will receive an Eastern Sierra Mussel Sticker and can launch.
What happens if my boat does not pass inspection?
If your boat is not clean, drained, and dry—or is considered high risk—you will be required to go through decontamination before launching.
What is decontamination?
Decontamination is a process performed by trained staff using high-temperature, high-pressure water to kill any invasive mussels or larvae.
This is required if:
- Your boat is not clean, drained, and dry, or
- Your boat was recently used in waters outside Mono or Inyo County
Can I refuse an inspection?
You can refuse an inspection, but your boat will not be allowed to launch, and doing so may result in a violation of local ordinance.
How long does inspection or decontamination take?
Inspection is typically quick (a few minutes). Decontamination may take longer depending on the size and condition of the vessel.
Also: please do not release live bait or bait water into any waterbody.
This is prohibited in Mono and Inyo Counties and helps prevent the spread of golden mussels and other invasive species.
Additional Resources – More Golden Mussel Information
California’s Invaders: Golden Mussel
Golden Mussel Fact Sheet
Clean, Drain, Dry (and Inspect!) – Every Time!
Local visitor information
Mono County Tourism: https://www.monocounty.org/
Mono County Recreation: https://monocounty.ca.gov/sustainable-recreation
Mammoth Lakes Tourism: https://www.visitmammoth.com/
Town of Mammoth Lakes: https://www.townofmammothlakes.ca.gov/1147/Office-of-Outdoor-Recreation
Bishop Chamber of Commerce: https://bishopvisitor.com/
Inyo County: https://inyocountyvisitor.com/
Responsible Fishing/Tangle Free Waters
More information coming soon!
https://mammothlakesrecreation.org/tangle-free-waters
https://www.monocounty.org/things-to-do/fishing/sustainable-fishing