The term national park has public meaning and institutional definition. The first derives from an ideal, promoted by prominent citizens between ca. 1850 and 1970 that, through the preservation and enjoyment of spectacular natures in parks a sense of nationhood, cultural identity and citizenship could be forged or reimagined. In this sense, National Parks act as a brand. Subsequently, the national park term has acquired an institutional definition within the protected area categorisations of the IUCN. This specifies that national parks should be "large areas in an 'intact natural state' protected to conserve biodiversity and functioning ecosystems, to educate and excite people concerning the need for conservation and to provide a foundation for tourism economies". In the IUCN sense, national parks are resource reserves of national significance with the potential to generate co-benefits. Conflating these two distinct concepts of national park within international policy and conservation science has served to generate ambiguity concerning the purpose and implemetation of this 'gold standard' of place-based conservation.
At a time when identity politics is on the rise and international finance for biodiversity is in decline we suggest it is relevant to disaggregate national parks into those that play a role in 'branding' and shaping cultural identities and those that are primarily concerned with the conservation of biodiversity and ecosystem services. To this end we we have developed a 'Yellowstone Index' of public interest in national parks as a heuristic tool for reassessing their role in public policy. Our index is calcualted from Wikipedia page view data and can be applied at multipe scales. We demonstrate distinct geographies for iconic parks and reveal different national approaches to national park policy. Our Yellowstone index offers a heauristic tool for reassesing the role of national parks in public policy. It supports among other things: i) mapping and quantifying the degree to which nature conservation is part of the cultural identities of nations and regions, ii) identification of NPs and associated natural features that support, of have the potential to support, place branding and tourism economies, iii) identifications of NPs with little public interest and that may be at risk if political support changes in favour of economic land development. Perhaps mostly importantly it enhances democratic transparency of national park policy and thereby the potential to reinvigorate and align the national park designation with wider trends in society.