Why do some counties produce so many entries?

Answering this question is difficult since so many natural and man-made factors come to bear. Still, the relationship between record book entries and river systems is plainly evident throughout the country, especially in heavily farmed states. For example, in Iowa the best deer counties are not the most heavily farmed, but tend to have a mixture of farmland and forest cover associated with river bottoms. Counties bordering the Missouri, Mississippi and Des Moines Rivers account for the majority of entries from Iowa. This pattern is evident in nearly all states, especially along the Mississippi, Ohio, and Missouri River systems.
The relationship between deer densities and number of entries is also interesting. States with high deer densities and long firearms seasons with liberal bag limits produce, on balance, fewer entries. States with lower deer densities, shorter gun seasons, and more restrictive buck harvests tend to produce more entries. A good comparison is between Ohio, which averages around 10 deer per square mile, and Mississippi, which averages more than 30.

The all-time best counties are Buffalo, WI, and St. Louis, MN with both recording 62 entries.