Every alert comes with a KML, the block's shape in a file your mapping app can read. Here are short, current steps for the four common ones, on phone and on desktop.
Source: CalTopo Training, Importing Objects.
Source: Gaia GPS Help (iOS, Android, web).
Source: Avenza Maps, Importing map features.
Source: Google Earth Help, import KML.
Join Cutblock Watch and the KML arrives with every block, ready to drop into the app you just set up.
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