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American Whitewater

Idaho Navigability Report


Idaho has one of the most boater-friendly rights of passage in the nation. Streams that can be floated by a kayak in Idaho are open to the public for any recreational purpose. Boaters may lawfully scout within ordinary high-water marks and portage around obstructions so long as they return to the river at the first safe spot.

State Test of Navigability

Idaho has adopted a recreational boating test to determine which streams are navigable, and therefore subject to a public easement. Consequently, the public can use more streams in Idaho than just those streams that pass the federal navigability tests.1) For purposes of recreational use, Idaho statute defines navigable streams as ”[a]ny stream which, in its natural state, during normal high water, will float cut timber having a diameter in excess of six (6) inches or any other commercial or floatable commodity or is capable of being navigated by oar or motor propelled small craft for pleasure or commercial purposes.”2) A list of streams considered to be navigable is also available from the Idaho Department of Water Resources.3)

Extent of Public Rights in Navigable and Non-Navigable Rivers

Navigable streams are “highways for recreation.”4) Recreational use of navigable streams is authorized “within the meander lines or, when not meandered, between the flow lines of ordinary high water thereof, and all rivers, sloughs and streams flowing through any public lands of the state shall be open to public use as a highway for travel and passage, up or downstream, for business or pleasure, and to exercise the incidents of navigation - boating, swimming, fishing, hunting, and all recreational purposes.”5) This statute passed shortly after a case in which Silver Creek in Blaine County was deemed navigable for all recreational purposes because it had been used for floating timber.6)

A more recent case highlights that the ordinary high-water mark may be open to interpretation. In the Sanders Beach case, the Idaho Supreme Court's findings as to the ordinary high-water mark eliminated public access to a beach that has been used by swimmers for a century.7)

Portaging over private land and around irrigation dams or other obstructions that interfere with the navigability of the stream is expressly permitted by statute.8) The boater must reenter the stream immediately below the obstruction at the nearest point where it is safe to do so.9)

Trespassing on property that is posted against trespassers with signs or painted fence posts, or where oral or written personal communication to leave the property is given by the owner or lessee, is a misdemeanor.10)


Legislative amendments passed in 1996 in response to agricultural, timber and mining interests limit the applicability of the public trust doctrine in Idaho. Specifically, the statute provides that land use and water management decisions are to be made without reference to the public trust. Although the statute does not directly impact the public's recreational use of streams, decisions that consistently put business interests first could negatively impact the public's ability to enjoy streams for recreational purposes over time.11)

1) Idaho Code § 58-1201(a) (2006) (expressly recognizes that Idaho holds the beds of streams navigable under the federal title test in trust for the public). See Selkirk-Priest Basin Association, Inc. v. State, 899 P.2d 949 (Idaho 1995) for a recent application of the public trust doctrine for navigability purposes in Idaho, but note that this decision was before the legislative amendments discussed in the Miscellaneous section. See also Fishing From the Bank: Public Recreational Rights Along Idaho’s Rivers and Lakes, 21 Idaho L. Rev. 275 (1985).
2) , 4) Idaho Code § 36-1601(a) (2006).
3) The listing is included in the Attachments to 2007 Idaho Department of Water Resources Recreational Dredging Application. A copy is on file with AWA.
5) Idaho Code § 36-1601(b) (2006).
6) Southern Idaho Fish and Game Ass’n v. Picabo Livestock, Inc., 528 P.2d 1295 (Idaho 1974).
7) City of Coeur D’Alene v. Michael L. and Jeannette G. Mackin, et al. and State Board of Land Commissioners, et al., 147 P.3d 75 (Idaho 2006). See also Idaho Forest Industries, Inc. v. Hayden Lake Watershed Improvement District, 17 P.3d 260 (Idaho 2000) for a discussion of the determination of the “ordinary high-water mark.”
8) , 9) Idaho Code § 36-1601 (2006).
10) Idaho Code § 18-7008 (2006).
11) Idaho Code § 58-1203 (2006) (enacted through House Bill No. 794 of 1996). See Closing the Floodgates? Idaho’s Statutory Limitation on the Public Trust Doctrine, 34 Idaho L. Rev. 91 (1997) for further background and analysis.