First navigate to the USGS Map Locator and Downloader Web Page
Now Double-Click to Zoom-In and Click-and Drag to Re-center the interactive map until you get to the area you want.
Next Select “O MARK POINTS: “ instead of “O NAVIGATE: “ on the right side of the window. If you are not zoomed in too tight this will cause grid lines to appear. These indicate the approximate borders of the most recent maps available.
There is a Pull-Down window near the middle of the right side of the window indicating either “30 Minute and larger” or “7.5 to 15 Minute”. The “30 Minute and Larger” refers to maps covering about 30 miles by 30 miles or larger. Always use the “7.5 to 15 Minute” selection. I will explain why in a minute.