![Figure][1] Flathead River CREDIT: ©GARTH LENZ/[WWW.GARTHLENZ.COM][2] The Flathead River, which originates in British Columbia and flows into Montana, is considered one of America's wildest rivers. Its water quality is pristine, it harbors abundant and diverse aquatic life, and it sustains the full complement of mid- to large carnivores that have lived there since the 1800s. Time and time again since the mid-1970s, the river has been threatened by British Columbia's plans to strip mine for coal. In 2007, British Petroleum announced plans for coal-bed methane development in the basin ([ 1 ][3]). The swift response, which successfully prevented these plans from coming to fruition, included three elements: a careful scientific analysis, a fact-finding mission that respected the scientific input, and a productive diplomatic relationship that resulted in policy changes. First, the United States responded by developing a science team to conduct a comprehensive environmental assessment of water quality, aquatic food webs, habitat, native fish, and wildlife. The science was compelling. A comparison between data collected from the Flathead and from the neighboring Elk River, the site of more than 50 years of open-pit coal mining, showed that waters of the Elk basin were significantly more polluted than those of the Flathead: Elk basin had more than 1000 times the nitrates, 100 times the sulfates, and 10 times the selenium concentrations. Similarly, aquatic food webs in coal mine–affected waters lost biodiversity as many pollution-sensitive species disappeared ([ 2 ][4]). In contrast, the pristine water and aquatic habitats in the Flathead support migratory populations of endangered species such as bull trout and nonhybridized westslope cutthroat trout ([ 3 ][5]). In September 2009, a joint United Nations Educational, Scientific, and Cultural Organization (UNESCO)/International Union for Conservation of Nature fact-finding mission visited the Flathead in Montana and British Columbia to investigate whether the proposed mining was a threat to Waterton-Glacier International Peace Park, a UNESCO-designated World Heritage Site and Biosphere Reserve. The UNESCO mission listened carefully to the scientists' results. Their report concluded that mining in the Flathead would be “incompatible” with Waterton-Glacier as a World Heritage Site ([ 4 ][6]). Finally, diplomacy at the state/provincial level and at the federal level between the United States and Canada was developed through personal relationships and mutual interest. Policy-makers in both countries respected the scientific and fact-finding analyses. As a result, on 18 February 2010, Premier Gordon Campbell of British Columbia and Governor Brian Schweitzer of Montana signed an accord to prohibit coal mining, coal-bed methane extraction, and gas and oil exploration and development in the transboundary North Fork of the Flathead River Basin. Throughout this process, scientific results played a central role in providing the backbone for resolute policy and the case for relentless political pressure. This healthy precedent will allow science to continue to inform policy as Canadian and U.S. officials work together to develop a natural-resource policy that protects this remarkable, shared ecosystem. We believe that this case will stand as an international model in which the natural goods and services provided by a World Heritage Site and Biosphere Reserve were ultimately valued over the commodities of natural-resource extraction. 1. [↵][7]1. J. Mann , “Coal-bed permits sought,” The Daily Inter Lake, 9 August 2007; [www.dailyinterlake.com/news/local\_montana/article\_a58f4503-95e5-5b93-a73e-06319bc91e47.html][8]. 2. [↵][9]1. F. R. Hauer, 2. E. K. Sexton , “Transboundary flathead water quality and aquatic life: Biennial report” (Flathead Basin Commission, Kalispell, MT, 2010). 3. [↵][10]1. C. C. Muhlfeld, 2. T. E. McMahon, 3. D. Belcer, 4. J. Kershner , Can. J. Fish Aquat. Sci. 66, 1153 (2009). [OpenUrl][11][CrossRef][12][Web of Science][13] 4. [↵][14]1. P. R. Dingwall, 2. K. Rao , “Report of the reactive monitoring mission” (UNESCO World Heritage Centre, International Union for Conservation of Nature, Waterton-Glacier International Peace Park, 2009). [1]: pending:yes [2]: http://WWW.GARTHLENZ.COM [3]: #ref-1 [4]: #ref-2 [5]: #ref-3 [6]: #ref-4 [7]: #xref-ref-1-1 View reference 1 in text [8]: http://www.dailyinterlake.com/news/local_montana/article_a58f4503-95e5-5b93-a73e-06319bc91e47.html [9]: #xref-ref-2-1 View reference 2 in text [10]: #xref-ref-3-1 View reference 3 in text [11]: {openurl}?query=rft.jtitle%253DCan.%2BJ.%2BFish%2BAquat.%2BSci.%26rft.volume%253D66%26rft.spage%253D1153%26rft_id%253Dinfo%253Adoi%252F10.1139%252FF09-073%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [12]: /lookup/external-ref?access_num=10.1139/F09-073&link_type=DOI [13]: /lookup/external-ref?access_num=000267874300012&link_type=ISI [14]: #xref-ref-4-1 View reference 4 in text