AlaskaRegion_NWRs_all

Tags  Arctic, Becharof, Innoko, Izembek, Kanuti, Kenai, Kodiak, Koyukuk, Alaska Maritime, Nowitna, Alaska Peninsula, Selawik, Tetlin, Togiak, Yukon Delta, Yukon Flats, National Wildlife Refuge, NWR, USFWS, FWS, boundary, generalized, unofficial

Summary

These polygons depict simplified boundaries of the 16 National Wildlife Refuges in Alaska for quick reference.

Description

This feature class was generalized from U.S. Fish and Wildlife Service cadastral data, specifically the Approved Acquisition Boundaries (available at https://ecos.fws.gov/ServCat/Reference/Profile/131755). A subset of this national data set was first exported to include only features within the Alaska Region. This new feature class was then projected to a local coordinate system, NAD83 Alaska Albers. 
1. ARCTIC
Polygons representing Arctic NWR were exported to a new feature class, which was further simplified using Esri's Generalize tool, with a simplification tolerance of 300 meters. The resulting polygon feature has 465 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
2. BECHAROF
Polygons representing Becharof NWR were exported to a new feature class, which was further simplified using Esri's Generalize tool, with a simplification tolerance of 100 meters. The resulting polygon feature has 464 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
3. INNOKO
Polygons representing Innoko NWR were exported to a new feature class, which--after removing small polygons less than 100 square kilometers (using Esri's Eliminate Polygon Part tool)--was further simplified using Esri's Generalize tool, with a simplification tolerance of 50 meters. The resulting polygon feature has 315 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
4. IZEMBEK
Polygons representing Izembek NWR were exported to a new feature class, which was simplified using Esri's Generalize tool, with a simplification tolerance of 50 meters. The resulting polygon feature has 419 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
5. KANUTI
Polygons representing Kanuti NWR were exported to a new feature class containing one polygon with 450 vertices, requiring no further simplification. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
6. KENAI
Polygons representing Kenai NWR were exported to a new feature class, which was simplified using Esri's Generalize tool, with a simplification tolerance of 50 meters. The resulting polygon feature has 453 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
7. KODIAK
Polygons representing Kodiak NWR were exported to a new feature class, which was simplified using Esri's Generalize tool, with a simplification tolerance of 600 meters. The resulting polygon feature has 486 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
8. KOYUKUK
Polygons representing Koyukuk NWR were exported to a new feature class, which was simplified using Esri's Generalize tool, with a simplification tolerance of 75 meters. The resulting polygon feature has 452 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
9. MARITIME
Polygons representing Alaska Maritime NWR were exported to a new feature class, which was simplified using a combination of manual edits and Esri's geoprocessing tools. The final feature class contains 12 polygons, the largest of which has 495 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
Since Alaska Maritime NWR includes thousands of small islands, the first simplification step was to remove small polygon features less than 10 square kilometers. Then, neighboring polygons (within 95 kilometers of one another) were grouped using Esri's Aggregate Polygons tool. The output required some manual edits to remove vertices where sharp, dramatic points had been created (presumably due to small islands pulling polygon features in odd directions). This aggregated feature class was then simplified using Esri's Simplify Polygon tool, with a simplification tolerance of 1 kilometer and the Weighted Area simplification algorithm and a minimum area of 10 square kilometers. The output was further simplified using Esri's Smooth Polygon tool, with a 45-kilometer tolerance and the PAEK smoothing algorithm. Finally, manual edits were made to avoid overlap with adjacent refuge boundaries (Kodiak NWR, Izembek NWR, and Alaska Peninsula NWR).
10. NOWITNA
Polygons representing Nowitna NWR were exported to a new feature class, which--after removing small polygons less than 100 square kilometers (using Esri's Eliminate Polygon Part tool)--was further simplified using Esri's Generalize tool, with a simplification tolerance of 25 meters. The resulting polygon feature has 341 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
11. PENINSULA
Polygons representing Alaska Peninsula NWR were exported to a new feature class, which--after removing small polygons less than 150 square kilometers (using Esri's Eliminate Polygon Part tool)--was further simplified using Esri's Generalize tool, with a simplification tolerance of 550 meters. The resulting polygon feature has 473 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
12. SELAWIK
Polygons representing Selawik NWR were exported to a new feature class, which was simplified using Esri's Generalize tool, with a simplification tolerance of 150 meters. The resulting polygon feature has 449 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
13. TETLIN
Polygons representing Tetlin NWR were exported to a new feature class, which was simplified using Esri's Generalize tool, with a simplification tolerance of 75 meters. The resulting polygon feature has 409 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
14. TOGIAK
Polygons representing Togiak NWR were exported to a new feature class, which was simplified using Esri's Generalize tool, with a simplification tolerance of 100 meters. The resulting polygon feature has 473 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
15. YUKON DELTA
Polygons representing Yukon Delta NWR were exported to a new feature class, which--after filling holes and removing small polygons less than 100 square kilometers (using Esri's Eliminate Polygon Part tool)--was further simplified using Esri's Generalize tool, with a simplification tolerance of 425 meters. The resulting polygon feature has 490 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
16. YUKON FLATS
Polygons representing Yukon Flats NWR were exported to a new feature class, which was further simplified using Esri's Generalize tool, with a simplification tolerance of 425 meters. The resulting polygon feature has 483 vertices. Prior to exporting as geoJSON, the feature class was projected from NAD83 Alaska Albers to WGS 84.
Note that topology was not enforced during simplification or merging of feature classes, resulting in overlapping boundaries between some refuges, such as Alaska Peninsula NWR and Becharof NWR.
This feature class depicts simplified boundaries of all 16 National Wildlife Refuges in the Alaska Region and warrants the following limitations:
 1) must not be used for official or legal  purposes such as acreage computations or the field location of Refuge boundaries.
 2) intended to be used only for small-scale (<1:5,000,000) depiction of the Refuge boundaries.
If you require the official, full-resolution boundaries of the National Wildlife Refuges in Alaska, you may download them at https://www.fws.gov/r7/nwr/Realty/data/LandMappers/Public/Help/HTML/NationalWildlifeRefugeandWildern.html

Credits

USFWS, Alaska Region

Use limitations

For small-scale, general use/depiction of Refuge boundaries. Do not use for official or legal purposes. Do not use for legal or official acreage computations.

Extent

Scale Range