The Hope Mountains, and the "Anderson River Group" are separated from the main Skagit Range by distinct natural boundaries, but are otherwise similar in character.

[2] According to Fred Beckey there are differences of opinion about the names and locations of the subranges of the northern Cascades, especially between Canadian and American geographers.

Nevertheless, early geologists and topographers had a fundamental agreement about the location and names of the subranges.

More recent Canadian maps show the Skagit Range as bounded to the west by the Sumallo-Nicolum valley and extending north along the east side of the Coquihalla River.

[2] BCGNIS defines the Skagit Range simply as "west of the Skagit River, extends into the U.S.A."[3] The USGS defines the range in its GNIS database with a single point, 48°55′39″N 121°33′57″W / 48.92750°N 121.56583°W / 48.92750; -121.56583, north of Granite Mountain where Mount Chardonnay is situated.