Company Location Rose Bertram LLC, The Fond du Lac Area Retirement Planning & Investment Resource, is located at 19 East 1st Street, Fond du Lac WI 54935.Rose's office is easy to find and access in Fond du Lac. From Main Street, turn east on First Street. The office is located one block east of Main Street on First, at the intersection of First and Portland. It is the tan colored stucco-three story office building with brown awnings. Rose Bertram LLC is listed on the awning and on the door.Street parking is plentiful.