The McGregor Historical Museum (254 Main St.; 563.873.2221) has an informative collection of exhibits, mostly focused on characters who inhabited the area. The most impressive pieces are the sand bottles created by Andrew Clemens; you should visit the museum for this reason alone.
It took a while to complete, but the United Methodist Church (330 Ann St.; 563.873.2409) was worth the wait. Construction began in 1852 but the building was not completed until 1873. Inspired by Centenary Church in Chicago, the building is primarily Romanesque in design, but its 151-foot tall towers are topped with Mansard roofs.
The congregation of St. Mary’s Catholic Church (311 7th St.; 563.873.2665) organized in 1855; the current church, built next to the bluff at the foot of Main Street, was completed in 1882. Just six years later, a catastrophic Christmas Day fire destroyed the interior; parishioners quickly repaired the church. The building got a top-to-bottom makeover in 1977, with an eye toward preserving important historical details: the main altar and sacristy were restored to their original appearance and the art glass windows were repaired. The interior has some beautiful wood: butternut for the main altar, cherry in the sanctuary, pews of red oak, and cedar crossbeams in the ceiling.
The Agri Aerie is a large deck that overlooks the Agri Grain Marketing elevator and the river. You can walk to it from Main Street via 2nd Street.
At the top of the hill after you leave McGregor on County Highway X56 is the entrance to Pikes Peak State Park (563.873.2341), named after explorer Zebulon Pike. The park has the standard amenities (hiking trails, picnic tables, campgrounds, mountain biking, burial mounds) but the real treat is the spectacular overlook and its expansive views 500 feet above the Mississippi and Wisconsin Rivers. Most visitors only visit the overlook, so if you explore the trails, you are likely to escape the crowds.
Sitting atop Swede Ridge on County Highway X56 just south of Pikes Peak State Park, First Lutheran Evangelical Church (County Highway X56) the Old Norwegian Church is a simple frame “preaching box” with a tower. Built as the Norwegian Evangelical Lutheran Church in 1861, this may be the oldest frame church west of the Mississippi. The interior has simple accents: wood carving on the chancel, a carved pump organ, oil lamps (the building has no electricity), white and gold trimmed altar, and mini wooden collections baskets. The congregation merged with Swedish Lutheran Church in 1936 and moved into the bigger church; this building sat empty until its restoration from 1970–1972. If you are interested in a tour, contact the McGregor-Marquette Chamber of Commerce (563.873.2186).
McGregor Riverfront Park (Main & 1st Streets) is a pleasant place to sit and watch the river roll by. McGregor Triangle Park (Main Street, 1st Street & A Street) is a hub of summer activity.