The applicable sections of the Colorado Revised Statutes are:
CRS § 18-4-504 which defines third degree criminal tresspass: "(1) A person commits the crime of third degree criminal trespass if such person unlawfully enters or remains in or upon premises of another."
and CRS § 18-4-504.5 which defines "premises" to include "stream banks and beds of any nonnavigable fresh water streams flowing through such real property"
The question of what is navigable and whether or not the public has the right to float through private land (without touching banks and beds) is not clearly defined in state law. However, most people are operating under the opinion of Attorney General Duane Woodard in 1983:
"(t)he intent, purpose, and effect of section 18-4-504.5 is to protect adjoining property owners from trespasses to the banks and beds of streams and exempt those who float upon the state's waterways from criminal trespass liability. Since the statute speaks only to criminal trespass, it does not address the question of civil remedies and therefore cannot be viewed as providing authority for private owners of stream banks and beds to prevent such use of the water."
To read the Colorado Revised Statues, go to:
and click on "CO Revised Statutes"
For a good summary memo about the situation (as of June 1999), go to:
and search for:
memorandum trespass "june 8, 1999"