Parents are Mary Jo Sitzmann of Le Mars, Charles Sitzmann of Rogers, Ark., and Jack and Joyce O'Toole of Dubuque.
Maids of honor were the bride's sisters-in-law, Holly Sitzmann of Washington, D.C. and Melissa Sitzmann of Henderson Nev. Bridesmaids were Molly Carpenter of Dubuque, sister of the bridegroom, and Wendy Peters.
Tracy Powers of Dubuque was best man. Groomsmen were Brandon Sitzmann of Washington, D.C., brother of the bride; Ryan Sitzmann of Henderson, brother of the bride, and Bill Carpenter, Dubuque, brother-in-law of the bridegroom.
Seating the guests were Jason Conrad, Jesse Thompson and Dan Sherman of Dubuque.
The reception was held for 200 guests following the ceremony at the Le Mars Convention Center.
Erin is a graduate of Loras College, Dubuque, and Arizona State University. She is employed at Value Options in Phoenix, Ariz.
Sean served in the U.S. Marine Corp and attended the University of Iowa. He is employed with the America West Airlines in Tempe, Ariz.
Following their wedding trip to San Francisco, the couple is at home in Gilbert.