The Ashnola River is a tributary of the Similkameen River, rising in the northeastern part of the North Cascades in Washington, United States, and flowing north into British Columbia, Canada, to join the Similkameen River about halfway along that river's course between the towns of Princeton and Keremeos. The river crosses the international boundary at 49°00′00″N 120°19′37″W / 49.00000°N 120.32694°W and transits Cathedral Provincial Park. It has one main tributary, Ewart Creek, which is about 25 kilometres (16 mi) long and begins virtually at the border and is entirely within Cathedral Park.
A gravel road from its junction with BC Highway 3 at the locality of Ashnola flanking the river is the main, and virtually only, road access to the park. The locality of Ashnola was that of a mining camp from the days of the many gold rushes in the Similkameen Country and also the site of the Ashnola Indian Reserve (attached to the Lower Similkameen Indian Band).
Name variants and origin
Older name-variants includes Nais-nu-loh and Ashtnolow (both from Lord, 1860), Ashtnoulou (1861), Ashnoulou River, Trutch, 1871. An article in BC Motorist magazine claims that the meaning of Ashnola is "white waters" but other sources say the meaning is unknown. British Columbia Place Names, a semi-authoritative work on the toponymy of British Columbia, says the original form of the name is that of the Indian village formerly at the Ashnola Indian Reserve, which in the modern spelling system of the Okanagan language is rendered Acnulox.
- "Ashnola River". BC Geographical Names.
- "Ashnola River". Geographic Names Information System. United States Geological Survey.
- Living Landscapes website index, British Columbia Provincial Museum, item 14*04 SIMILKAMEEN INDIAN ADMINISTRATION (KEREMEOS), RECORDS EST. CA. 1971
- Wild Land of the Ashnola by Jennifer Maynard, BC Motorist magazine July-Aug 1971, p.14
- British Columbia Place Names, Akrigg, Helen B. and Akrigg, G.P.V, Sono Nis Press, Victoria 1986 /or University of British Columbia Press 1997.