Rock Cut State Park is located northeast of Rockford. It is bisected by I-90. A convenient exit is located at the intersection of I-90 and IL 173. Proceed west from the exit ramp (toll at this spot-no cash, only IPass) to the main entrance off of IL 173.
The entry road will pass through a planted prairie and then into scrubby second growth. This area should be checked for Northern Shrikes in March and sometimes Loggerhead Shrikes in late March/early April. The shrikes are often in the vicinity of the campground. Turn left at the first stop sign and drive 500 feet to the campground entrance. The loop road is closed beyond the campground entry during the winter, but you can enter the campground. Once the roads are cleared of snow, the gates are often opened and the full loop road can be accessed. On the entry road into the campground, look for a variety of sparrow species, particularly Fox, Song, American Tree and juncos. n early Hermit Thrush might be in their company.
Once you check the campground, retrace your path back to the stop sign intersection on the loop road and turn left toward Pierce Lake. The road will pass through upland hardwood forest which is pretty empty of birds during winter, so keep going to the parking lot by the dam at the west end of Pierce Lake. The deepest part of the lake is just east of the dam. Check the open water on the lake. If the lake is open, there are several other spots to check for waterfowl, including the Red Oak picnic area. Continue on the loop road across the dam and follow it past the concession stand to the driveway to Red Oak. Park at the end of the lot up on the hill and walk down toward the lake for the best views.
The Olson Annex to Rock Cut SP is located on the east side of I-90. You can cross over I-90 on a small bridge from the main loop road and, at the stop sign, turn left toward the beach area. Olson Lake is much more shallow than Pierce Lake, and it freezes deeper, so it is later to open in the spring. Diving ducks are usually at the western end, near the dam/spillway, while the east end has puddle ducks.