The eastern turkey, found in Maine, will most likely be the easiest of the four sub-species on a hunter’s checklist. Others will require some planning and travel. Keith Srakocic/Associated Press

The term grand slam has been popularized by baseball, referring to a bases-loaded home run that scores four runs with one swing of the bat. While it takes more than one swing, the term was subsequently adopted by turkey hunters to describe collecting each of the four subspecies or races of wild turkeys found in North America: the Merriam’s, Rio Grande, Osceola and the eastern. While both baseball and spring turkey seasons are still months away, now is the time to start planning if your goal is a grand slam.

The Osceola or Florida turkey is typically considered the most difficult of the quartet, and often first on the list. Their range is limited to a single state where public land hunting is limited and guided hunts can be pricey, and sometimes troublesome to find openings for. If you want a reasonable expectation of success, you should start making inquiries and reservations now. Seasons begin as early as mid-March, providing a timely excuse to flee the frosty mornings in Maine for a more agreeable climate. Hunts usually entail waiting in and calling from a strategic location. Osceolas can be fickle, so patience and practiced calling are key components.

Next up is the Rio Grande. They have a much broader distribution, including the west coast, plains and mountain states and Texas. The latter is the most popular destination, as turkeys and outfitters are abundant, and the latter more reasonably priced compared to a Florida hunt. Public land opportunities exist, particularly in states like Oklahoma and Nebraska, but you’ll want to do your homework.

Rios are sometimes considered pushovers, and they can be. They can also be quite difficult, depending on things like local abundance, hunting pressure and timing. Seasons begin in mid- to late-April, providing a little spring training before you start the regular season back home. Check on local conditions, because states like Texas and Oklahoma have been subject to boom and bust cycles. One year, you’ll be overrun with jakes that will chase off older birds. The next may provide a plethora of longbeards for you to choose from.

Merriam’s can also be pushovers, but what they lack in wariness, they more than make up for in where they live. They prefer the rugged breaks and foothills of the mountain states and often travel long distances over the course of a day. You should expect to do likewise if you want to be successful, so in addition to planning, you should start working on the treadmill now, as well.

There’s plenty of public land in Montana, Wyoming, Colorado and the Dakotas, where you might find birds if you do your research. Guided or even semi-guided hunts are still a better option if you want to hedge your bets. The latter might include drop camps or merely access to unmolested private land.

Last – but by no means least – is the eastern, the range of which covers most of the eastern U.S. They’re widespread and abundant, but don’t look past them or you might end up frustrated. Depending on when and where you hunt, they can be among the most challenging, especially when hunting public land, or later in the season. If you have them close to home, make sure you reserve the first few days of the local season to tick them off your list. Should you fail, you can always come back again after bagging the other three.

There are no hard rules about how long you take to complete your slam. Many hunters try to do it in a single year, but you may opt to do one a year until you finish; then try to do your second slam in a single season.

There’s also some gray area as to what officially constitutes a distinct subspecies. Capture and relocation efforts have muddied the waters, and where races overlap, they often interbreed. Kansas and Oklahoma have both Rios and easterns, and broad swaths where hybrids occur. From a single camp in Nebraska, my hunting party harvested birds that, at least by plumage characteristics, included Rios, Merriam’s and easterns. Washington has distinct populations of all three in different regions, and northern Florida has both Osceolas and easterns.

Whether you’re looking to expand your experience, reach a milestone or merely spread your wings beyond your own state boundaries, consider going for a grand slam this spring. Start studying now, make plans and get your gear in order. It may be a long corner, but another spring turkey season is right around it.

Bob Humphrey is a freelance writer and Registered Maine Guide who lives in Pownal. He can be reached at: bhunt@maine.rr.com