Willow Creek is a stream located .9 mile from Mason City.

It was noted in the 1883 History of Franklin and Cerro Gordo Counties, Iowa:

"Lime creek and its main tributary, Willow creek, the outlet of Clear lake, which unite a half mile east of Mason City, are two very remarkable streams of the purest water. The former, in its entire course through a supposed circle, dashes over a rocky bed, and much of the way is walled in by precipitous ledges of lime rock, ranging from ten to fifty feet in height, while the latter stream, through the last two miles of its course, forces its way with an almost irresistible current through similar ledges of rock. The volume of water in these two streams affords ample supply for milling and manufacturing purposes, and so great is this fall that dams affording from eight to ten feet head may be built every mile of their course, without the interference one with another; and so high are these rock-bounded banks that but very little of the adjacent land can be in any case overflowed. H. G. PARKER, at his flouring mills, on the Willow creek, obtains a fall of ten feet, without setting back the water more than eighty rods. "

The stone arch bridge over Willow Creet on East State Street, Mason City, was built in 1903. N.M. Stark and Company of Des Moines were the architects. The bridge is located in the historic Rock Glen district.

The bridge, a closed-spandrel arch, has a deck width of 48 ft.; total length of 88 ft. and the length of the largest span is 62 ft.

While Walter Burley Griffin built the Joshua Melson house, he was so pleased that he felt the need to keep the site illuminated all through the night to accommodate on-lookers on the State Street Bridge. Melson joked that Griffin would have to pay the electric bill.

State Street Bridge was placed on the National Register of Historic Places June 25, 1998.