All component files of a shapefile are limited to a maximum size of 2GB. The data in Wildfire Risk Extreme is divided into 46 separate regions for distribution in this format. Region files are roughly equal in size (on disk) and fit together perfectly to create a seamless tessellation of the landscape from coast to coast. They are numbered and have short, iconic names as a convenient way to identify general location. These names and numbers appear only in file names and have no other significance or meaning within Wildfire Risk itself:
- Columbia
- Kalispell
- Fort Peck
- Land-o-Lakes
- Eureka
- Painted Hills
- Snake River
- Bighorn
- Standing Rock
- Headwater
- Green Bay
- Silver Dollar
- Salt Lake
- Laramie
- Sand Hills
- Hawkeye
- Windy City
- Motown
- Adirondack
- North Woods
- Cape Cod
- Big Sur
- Sierra
- Canyonlands
- Great Divide
- Dodge city
- Independence
- Wabash
- Bluegrass
- Chesapeake
- Mojave
- Navajo
- Santa Fe
- Cimarron
- Ozark
- Graceland
- Blue Ridge
- Pamlico
- Sonora
- Big Bend
- Sweetwater
- Texarkana
- Piney Woods
- Dixie
- Rio Grande
- Gulf Coast
- Alaska
- Hawaii