(KMZ files are zipped KML ones)
Use Google Earth, ArcGIS Explorer, or other programs to view conservation bank service areas superimposed on a map of California.
If you have one of the above programs set as your default KML/KMZ viewer, you will be asked whether you want to open or download the file.
Zoom in to see whether your project site is within a bank's service area.
Where to See Rare Species in Northern California
National Wetlands Inventory KMZ files. This page has more info on KML/KMZ files.
For more information see the Wikipedia article on Keyhole Markup Language.