I would like to know the current number of sightings reported in the area north of the Clark Fork River and South of Hwy 2, around the Cabinet Gorge Dam Area, for both black bears and grizzly bears.
The grizzly bear portion of your questions is timely and I can give you a pretty good answer. There was a large-scale effort to estimate grizzly bear numbers in the Cabinet Mountains that just ended last year. The sampling was comprised of collecting hair from grizzly bears from baited barbed-wire enclosures, then using the DNA from hair to identify individual grizzly bears. After an analysis of the year's sampling, the best population estimate of grizzly bears in the Cabinet Mountains is 22 bears, about equally split between males and females. The population could be as high as 39, but the best estimate is 22 bears. But keep in mind that this estimate is for the whole Cabinets that runs all the way down to the Plains and Thompson Falls area in Montana. The number of grizzly bears in the Idaho portion of the Cabinets is perhaps in the range of 10 bears, but grizzly bears do move quite a bit and some of these likely spend time in Montana and Idaho.
The black bear portion is much harder to answer because we haven't done the in-depth research on black bears that we have on grizzly bears. Density estimates for black bears in this area ranges from about 0.5 bears per square mile to 1.0 bear per square mile. The high estimate is based on very good quality habitat in the Priest Lake basin. The lower estimate is based on some trapping we have done in the St Joe, an area that isn't quite as productive from a bear standpoint. My guess is that the bear density lies somewhere between these two figures - perhaps in the range of .6 - .7 bears per sq mile. The area that you are talking about is perhaps 150 sq miles in size, so the area could support somewhere around 100 black bears, give or take. Please realize that this is a pretty rough estimate. I hope this answers your question.