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Boat ANS Inspection and Decontamination
Boat ANS Inspection and Decontamination
Aquatic Nuisance Species Stamp Required in Colorado Waters

Motorboats and sailboats must have an ANS Stamp prior to launching in Colorado waters.

Boat owners are required to purchase the ANS Stamp and operators must retain proof of purchase (electronic or printed receipt) on his or her person, the motorboat or sailboat, when operating the vessel (C.R.S. 33-10.5-104.5). 

Motorboats and Sailboats from Colorado - $25.00

  • Colorado residents will purchase the ANS stamp at the time of registration. If you register/renew your vessel online or via a registration renewal postcard, the cost of the ANS stamp appears as part of your total amount due. You do NOT need to manually add another $25 to your payment for an ANS Stamp.​​
  • Motorboats or sailboats documented by the U.S. Coast Guard or otherwise exempt from in-state registration can purchase purchase their ANS stamp online at​, or at any CPW office or sales location​​.

​​Motorboats and Sailboats from Another State - $50.00 

​Funding contributes to prevention and management of ANS in the state. To learn more about the ANS Stamp, visit our Frequently Asked Questions document. Thank you for protecting our waters and contributing to conservation in Colorado!


​​​​​​Know the Rules for Boating in Colorado and Prevent the Spread of ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Harmful Aq​uatic Nuisance SpeciesANS Inspection Brochure cover

Mandatory - Colorado is a mandatory boat inspection state meaning that ALL trailered and/or motorized watercraft are required to be professionally inspected by state certified personnel:

  • prior to launching in any water of the state after boating in a different state,
  • upon exiting any water in the state which is positive for an invasive species, and
  • any time an inspection is requested prior to entering or exiting a water body in Colorado.

See more about the statewide effort​ to prevent the spread of zebra and quagga mussels and other aquatic invasive species.

Check out the map of Statewide Watercraft Inspection and Decontamination Sites​​​​​​ in Colorado.

Boaters should take full advantage of Colorado's green seal and receipt program, which provides documentation of compliance and will reduce wait times to get through inspection station lines and get you on the water faster. All stations use green seals. However, waters that are positive for ANS use blue receipts, while waters that are negative use white receipts. For more details, visit the ​Colorado Parks and Wildlife's Watercraft Inspection and Decontamination Manual.

Every boater is required in regulation to Clean, D​​rain, and Dry​​ your boat, trailer and equipment every time you enter or exit any waters.  

​It is also required that boat operators remove all plants and pull all water drain plugs from the conveyance prior to leaving the lake or reservoir.  It is not legal to transport a conveyance over land with plants on board and plugs in place.

Please read the Boater’s Guide to Aquatic Nuisance Species (ANS) Inspections to educate yourself on the requirement to boat in Colorado and how you can protect our waters by helping to stop the spread of invasive species.

Latest Findings

How to Help Prevent the Spread of Invasive Species

Zebra and quagga mussels are a serious threat to Colorado waters. Invasive species such as the zebra mussel negatively influence the food chain for native fish. Zebra mussels remove major quantities of phytoplankton from the water.  Phytoplankton is food for larval and juvenile fish. To learn more about the negative effects of aquatic nuisance species, visit Western Aquatic Invasive Species and Protect Your Waters​.​


To help the Colorado Parks and Wildlife quickly identify new populations of this unwanted species please report any sightings to Robert Walters, Invasive Species Coordinator.

Please contact the Invasive Species Program at 303-291-7295 with any questions about ANS or other invasive species.​