While it is not a defining factor, the "Ottawa Valley", in general terms, is considered to include Eastern Ontario and Western Quebec. A detailed description, as approved by the Board of Directors on April 19, 2005, is as follows:
The Ottawa Valley area consists of:
- the area lying north of the Canada/US border in the St. Lawrence River from a point that intersects with the Canada/US border at 77° longitude in Lake Ontario and following that border in a north-easterly direction until it meets the Ontario/Quebec border, and
- the area lying west of a line extending along the Ontario/Quebec border from the Canada/US border in the St. Lawrence River north to the Ottawa River, then continuing north across the river to Quebec and follows highways 327 to 148 to 329 to where it intersects with highway #117 (The Trans-Canada Route) at Ste-Agathe-Des-Monts, and
- the area lying south of highway #117 from Ste-Agathe-Des-Monts to Grand Remous and then follows a line that continues westward through Deep River located on the south shore of the Ottawa River to the easterly limit of Algonquin Park; and finally
- the area lying east of a line that follows the border of Algonquin Park southeast until it intersects with Ontario highway #58, and then follows that highway in a westerly direction until it intersects with a secondary road on the right (that eventually becomes hwy. #62) then south and west on that road/highway 62 to Combermere. The boundary then follows a line running southeast to where it intersects highway #41 at Cloyne, and follows highway #41 south to Napanee, then continues on a line running due south along longitudinal line at 77° to a point in Lake Ontario where it intersects with the Canada/US border.