The Croton Unit is one of the largest contiguous segments of the Shimek State Forest, comprising some 1,000 acres. Located along the Des Moines River in southern Lee County, it has become well known as a reliable location for a number of species typically associated with the southeastern United States. In addition, the area is noted for vireos, both tanagers, and other woodland species. While birding the area has its rewards, it also presents challenges.
Ticks are abundant, and birders are strongly encouraged to use repellant and wear tall rubber boots.
To date, no Lyme Disease transmitting deer ticks have been found in the immediate area, but they have been found nearby. Chiggers can be abundant in summer but can also be controlled with repellant. Poison ivy is also abundant. Birders who are sensitive to the plant are encouraged to know the leaf and to avoid it. All Shimek Forest units are public hunting areas, but this should be of little problem during spring and summer outings.