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The need for security areas in which grizzly bears (Ursus arctos) may rarely encounter humans and maintain wary behavior is not explicitly addressed by cumulative effect modeling (CEM). In addition, CEM does not assess the value to bears of small areas left between zones of human disturbance. We developed a predictive GIS based model of adult female grizzly bear security areas in the Central Canadian Rocky Mountains to provide agency planners with a tool that addresses these shortfalls. Our study area included 4 major jurisdictions: Alberta provincial lands, British Columbia provincial lands, Kananaskis Country improvement district in Alberta, and National Park lands in both provinces. Starting with the total land base in each jurisdiction, we progressively removed areas of unsuitable habitat (e.g., rock and ice), habitat within 500 m of high human use (>100 human visits/month), and areas of insufficient size based on an average daily feeding radius (polygons <9 km2). We identified the remaining lands as secure areas. We then tested the hypothesis that female grizzly bear use of security areas differs from the landscape as a whole based on radio telemetry data. Of the 4 jurisdictions in the Central Canadian Rocky Mountains, the largest percent of secure habitat was on British Columbia provincial lands. Of the land surface area of the Banff, Yoho, and Kootenay National Parks, 48% is unsuitable for grizzly bears, primarily because it is composed of rock and ice. This is unfortunate, because it is assumed that these national parks form productive core refugia for grizzly bears. By reconstructing past human use and forecasting into the future for Banff National Park and Kananaskis Country, we demonstrate progressive loss of security areas. We found that an average of 69% of the land within grizzly bear home ranges was secure using our sample of 28 radiocollared adult females. Resource selection indices from these bears demonstrated selection of security areas within their home ranges. Existing mortality and translocation data, combined with our findings of low security and high habitat fragmentation within some adult female home ranges, give quantitative substance to the assertion that grizzly bears in and around Banff National Park and Kananaskis Country exist in one of the most human-dominated landscapes where they still survive. Access and development management are key to grizzly bear persistence in the region.