Glacier National Park leads off the list as America’s #1 ranked Last Great Place. Five National Parks are found in the top 25 Last Great Places, along with 14 Wilderness Areas. The #3 ranked Last Great Place honors one of America’s pioneering conservationists – the John Muir Wilderness in California’s Sierra Nevada.
Top 25 Last Great Places
The Last Great Places rank was determined on a 50-50 weighting of the site’s overall percentile rank (among ~50,000 sites) and its ecoregion percentile rank. This approach rewards the top places in all ecoregions. As a result, some overall highly ranked sites, such as Zion National Park (#16 rank overall but #4 ranked site in its ecoregion), are not on the top 25 list. Several places are included multiple times because they are treated as separate parcels in the PA database (e.g. Great Smoky Mountains National Park in NC and in TN). Click here to review Methods.
Click here for the downloadable, interactive Rankings spreadsheet. Sort and filter data to explore over 50,000 areas in the Protected Areas database by ecoregions, ranks, types, or scores for each of the eight ranking factors.
Key Findings
Total Area & Percent of Lower 48 States. The total portfolio of U.S. Protected Areas over 1 sq km — including Tribal lands but excluding state trust lands and after major overlaps were accounted for — was about 600 million acres, representing 30% of the 2 billion acres of land and water in the lower 48 states. The 2500 Last Great Places comprise about 137,000,000 acres or about 7% of the lower 48 states’ land and water.
Ecosystems & Percent Area Captured. The total Protected Areas portfolio captures all but two of the 706 natural ecosystems in the lower 48 states. Over 10% of their acres are captured for 80% of the ecosystems, and over 30% of their acres are captured for almost half of all ecosystems. The 2500 Last Great Places capture 94% of the ecosystems, and multiple examples of the vast majority of ecosystems. Unsurprisingly, many of the ecosystems not captured are small localized systems with less than 1000 acres nationwide.
Size. The largest Last Great Place was Death Valley National Park at over 3 million acres. The smallest Last Great Place was The Cedars State Natural Area Preserve on the Powell River, an imperiled species “hotspot” in southwestern Virginia, at 257 acres (the 1 sq km minimum)
Ecoregional Representation. The 2500 Last Great Places were well distributed across the 69 ecoregions. The top 100 places included 35 ecoregions, the top 500 places 56 ecoregions, the top 1000 sites 64 ecoregions, and all but one ecoregion was represented in the top 2500. The ecoregions with the largest number of highly rated sites were all in the western United States.
Key Findings: Ranking Factors
Land Facets. Larger sites, unsurprisingly, tend to have greater variety of landforms, slope/aspect, elevations and soil types. Nine of the top ten places for facet variety are all over 250,000 acres, including the top ranked Glacier and Olympic National Parks (the exception being the linear Pacific Northwest National Scenic Trail). The variety of land facets varies dramatically by ecoregion, from a high of 682 combinations in the mountainous Canadian Rocky Mountains to only 37 in the flat topography of Tropical Florida.
Ecosystems. Not unsurprisingly, there is a fairly high correlation (.68) between the variety of land facets and the variety of ecosystems at places. Size is an important driver of ecosystem diversity, but less so than with land facets. Over 2200 places have 25 or more different ecosystems. Ecosystem variety also differs by ecoregion, ranging from 26 to 121.
Rare and Imperiled Species Richness. Rare and imperiled species richness varies widely across the lower 48 states. The ecoregions with the most imperiled species habitat are several orders of magnitude greater than the least-rich ecoregion. The top places for imperiled species richness are found in four ecoregions, led by the Cumberlands & Southern Ridge and Valley ecoregion (with nine of the top 10 places), followed by the California Central Coast and East Gulf Coastal Plain. The Southern Blue Ridge ecoregion also has high imperiled species richness.
Human Modification. The top places for lowest human modification are found in the Great Basin ecoregion, with 41 unmodified places, followed by the Northern Appalachian/Acadian ecoregion with 12 places. Places with the highest modification are found in the highly developed North Atlantic Coast and California South Coast ecoregions.
Vegetation Condition. Four ecoregions have relatively low (under 40) mean ecological departure (i.e. good vegetation condition) – the Wyoming Basins, Colorado Plateau, Black Hills and Mojave Desert. 14 ecoregions have extremely high mean ecological departure (over 80), often due to agricultural conversion.
Resilience. The ecoregions with the highest mean resilience scores (over 700, on a scale of +1750 to -1750) were those with high geophysical relief (Black Hills, Utah-Wyoming Mountains, Southern Rocky Mountains and North Cascades. The lowest scores (under -800) were in two coastal / low-relief ecoregions (North Atlantic Coast and Florida Peninsula). Site resilience was somewhat idiosyncratic and influenced by site boundaries as well as their inherent geophysical features.
Conservation Management. Almost 800 of the top 2500 places had the best possible management score (i.e. GAP Status 1: managed for biodiversity, with natural processes). These were overwhelmingly Wilderness Areas, followed by national parks, state conservation areas, and national wildlife refuges. Another 1325 places had GAP Status 2 (managed for biodiversity, but with natural disturbances suppressed). 24 top places were GAP 4 (no mandate for protection), including 10 military installations.
Click here to download a Word document with detailed discussion of Results (coming in 2024).