Dennis J Mahr Law Offices Google Map 701 Pierce St #203, Sioux City, IA 51101 Located in: Commerce Building Dennis J Mahr Law Offices info Address: 701 Pierce St #203, Sioux City, IA 51101 Located in: Commerce Building Website: mahrlawoffice.com Telephone: (712) 233-1623 Zipcode: 68767 City: Pierce State: Nebraska Work Time: