Find a 7.5 Minute Quad

Our species database is set up by California counties and by U.S. Geological Survey 7½ minute quads. A quad is a geographical unit about the size of San Francisco. Learn more from the U.S. Geographical Survey web site.

Quad lists are much more precise than county lists (except for San Francisco County.) To get an online quad list, you must know the name or number of the quad or quads you want.

You can use the California Natural Diversity Database (CNDDB) Quick Viewer. It was not designed as a quad finder but it works well. See Instructions Below

The Quick Viewer was actually designed to give users a quick idea of what sensitive species are in each 7½ minute quad. (See Note)


Once you have launched the Quick Viewer, you should see a map of California. If you don't, click on the gold button that looks like the state. (It may take several seconds for the map to appear.)

You should see a large map of the state with county outlines and a grid of golden lines. Each of the boxes in that grid is a U.S.G.S. 7½ minute quad.

zoom in tool icon Use your mouse to zoom to the area that interests you. The easiest way to do this is to use your cursor to drag a box around the area of interest.

(The zoom feature should be turned on automatically. If not, turn it on by clicking on the button with magnifying glass that has a plus sign in it.)

zoom out tool icon If you zoom in too far, you can use the zoom out tool, a magnifying glass with a minus sign in it.

paw printYou can move around the map by selecting the panning tool - the red paw print. Use it to "grab" the map and move it around.

As you zoom in, you will eventually see recognizable features like roads. The name of each quad should be in the color teal at the center of the grid.

If you don't see the quad name, click on the colorful circular button. (It's the CNDDB logo.) The button has the letter i on it. Now click anywhere in the quad for which you want the name. You will get a list of species that have been recorded in that quad. The name of the quad will be at the top of the list.

To get a better idea of what species might be found in the quad, click on the first button that looks like a waffle. This will give you the species in a nine-quad block.

Note: The Natural Diversity Database contains the species that have been recorded in each quad. Our species lists cover all species that might be affected by projects in a quad. This could include species downstream from the quad, for example. It might also include species that probably exist in a quad but have never been officially recorded as being there. See our main species list page.)