First, try to get leads on potential areas by talking to game wardens, biologists (especially those who fly aerial duck surveys), county agents, commercial fishermen, mail carriers, school bus drivers, etc. (Don't bother seeking information from other duck hunters. They usually won't give up their secrets!) Keep detailed notes on what you learn. Consider yourself a sleuth trying to solve a mystery, and be creative in turning up possibilities.
As you accumulate leads, obtain maps of these target areas. United States Geological Survey (USGS) topo maps offer a wealth of information, showing swamps, marshes, oxbows and other small waters that ducks might use. They also reveal access to these places: logging trails, railroad beds, stream courses, etc. These maps are great for studying before a scouting trip and also for quick reference in the field. If you see ducks settling into a spot, you can get an accurate reference for where they're going.
(For information on ordering USGS topo maps, call 1-888-275-8747; or visit the USGS web site. When the home page appears, click on “Maps, Products & Publications,” then click on “Map Information.”) There are also several Web sites that provide detailed maps on-line. Just type “topographic maps” into your search engine.
Aerial photo maps may also show hidden duck holes. These can be obtained at local USDA Farm Service Agency offices. County road maps will help a hunter navigate through backcountry areas. Check for these at county highway departments.
Next comes in-the-field scouting, typically driving through the country during fall or winter and watching for ducks. If you spot a flight, try to follow it to see where the birds are going. The best times to scout are dawn and dusk, when ducks are on the move. Take a good pair of binoculars for better long-range viewing.
Pay special attention to watershed areas between two refuges or large duck concentration areas. When birds circulate to find food or rest areas, they frequently do so along creeks or rivers adjacent to their desired line of travel.
Of all scouting methods, perhaps none is more effective than renting an airplane and checking potential hunting spots from overhead. Small aircraft with a pilot typically rent for $100-150 per hour. Most local flight centers offer this service.
In an hour of flying/scouting, you can look at a lot of territory, and you will discover places that you never dreamed existed! Plus, when the migration is on, you can actually see ducks, so you will know beyond question which places they prefer. For serious duck hunters looking for new spots, there is no better investment than the money spent to hire a plane.
Make the most of your flight. Take binoculars for viewing and a GPS to mark potential hunting spots. Carry a camera, and photograph your discoveries. Also, take your maps on the flight, and mark areas that look promising. And when you locate one, circle around in the plane to find the best access to it. Knowing a hole exists is one thing. Figuring out how to get to it is another.