A similar, though not quite as pervasive, pattern of habitat and population fragmentation and local extinctions occurred in Canada. There are four remnant populations left within the contiguous states, three of which are shared with Canada. One survives in the North Cascade mountains of Washington and British Columbia. These bears have been federally listed as Threatened in the US, state listed as Endangered in Washington and provincially designated as Threatened in British Columbia. It is not known how many grizzly bears make up the remnant in the North Cascades.
Grizzly bears are extremely difficult to count under the best of circumstances.
They are secretive and occupy large homeranges. Grizzly bears do not defend discrete territories, but use areas sometimes as great as several hundred square miles in which to find food, mates and den sites. So it is difficult to quantify the number of bears living in any one area. In the North Cascades the task is made even more difficult, as bears have large areas of extremely rugged terrain and dense forests within which they can avoid detection by people. Current estimates of grizzly bear numbers in the North Cascades are based on information gained from observations by agency employees and the public.