Lannon Stone is actually dolomite. It's a type of limestone that runs through The Niagara Escarpment, which runs underneath most of the Great Lakes. In an area northwest of Milwaukee, in Waukesha County, the stone was found right on the surface. Settlers built thick-walled homes from the stone that they just lifted from the surface.
William Lannon was one of those settlers, and he recognized an opportunity to quarry and sell the stone. Quarries sprang up around an area surrounding "Lannon Springs" and the limestone that was quarried there became known as "Lannon Stone." (Today, stone homes are actually frame structures covered with a veneer of Lannon Stone.)

Many bridges in Southeastern Wisconsin, like the ones shown in this category, were built in the depression era and clad with a veneer of Lannon Stone.
Lannon Stone was widely used in the construction of structures in the Milwaukee County Parks. It is still widely used today, and in the Milwaukee County bridge listings, you will find some modern bridges, as well as replacement bridges, that are clad in Lannon Stone.
Cream City Brick can also be found in many Milwaukee area structures, including bridges. The soil in southeastern Wisconsin is red lacustrine clay. When it was used in the manufacture of bricks, the clay turned a yellowish-cream color when fired. So many structures in the Milwaukee area were built using the bricks that visitors began to call Milwaukee "The Cream City." As a result, the bricks became known as "Cream City Brick."
Cream City Bricks were distributed widely. Many lighthouses around the Great Lakes and buildings in Chicago, were constructed with Cream City Bricks.
As you look at the bridges in Southeastern Wisconsin, you will see many of them are clad with Lannon Stone and some with Cream City Brick. You might also notice many buildings and homes, in the background, that use these distinctive materials.
Brown Deer Parkway Bridge (Milwaukee County, Wisconsin)
Columbia Road Bridge (Ozaukee County, Wisconsin)
Highland Drive Bridge (Ozaukee County, Wisconsin)
Honey Creek Bridge (North of Bluemound) (Milwaukee County, Wisconsin)
Honey Creek Bridge (S. 84th Street) (Milwaukee County, Wisconsin)
Honey Creek Bridge (Wisconsin Avenue) (Milwaukee County, Wisconsin)
Honey Creek Bridge Two (Milwaukee County, Wisconsin)
Honey Creek Footbridge (Milwaukee County, Wisconsin)
Honey Creek Parkway Bridge (South of Bluemound) (Milwaukee County, Wisconsin)
Honey Creek Parkway Bridge One (Milwaukee County, Wisconsin)
Honey Creek Portland Avenue Bridge (Milwaukee County, Wisconsin)
Hubbard Park Drive Bridge (Milwaukee County, Wisconsin)
Lac La Belle Bridge (Waukesha County, Wisconsin)
Lincoln Creek Bridge (Milwaukee County, Wisconsin)
Milwaukee River Parkway, Lincoln Park, North Branch (Milwaukee County, Wisconsin)
Milwaukee River Parkway, Lincoln Park, South Branch (Milwaukee County, Wisconsin)
N. Teutonia Avenue Bridge (Milwaukee County, Wisconsin)
Oak Creek Mill Road Bridge (Milwaukee County, Wisconsin)
Oak Creek Parkway Bridge (Milwaukee County, Wisconsin)
Oakwood Avenue Bridge (Waukesha County, Wisconsin)
Oconomowoc River CPRR Arch Bridge (Waukesha County, Wisconsin)
Palm Tree Road Bridge (Fond du Lac County, Wisconsin)
Port Washington Road Bridge (Milwaukee County, Wisconsin)
Promen Drive Bridge (Fond du Lac County, Wisconsin)
Promen Drive Bridge (Fond du Lac County, Wisconsin)
Range Line Road Bridge (Milwaukee County, Wisconsin)
River Road Bridge (Waukesha County, Wisconsin)
W. North Avenue Bridge East (Milwaukee County, Wisconsin)
W. North Avenue Bridge West (Milwaukee County, Wisconsin)