The pipeline that crosses the Minnesota River near Granite Falls was built and operated by Williams Brothers, and is now owned and operated by Magellan Midstream Partners. The pipeline carries refined petroleum products such as gasoline and diesel fuel. The major source of these products is the Pine Bend Refinery located in Rosemont, Minnesota, and operated by Koch Industries under a subsidiary named Flint Hills Resources. The pipeline is 8 inches in diameter as it crosses the Minnesota River.
This pipeline begins at the Pine Bend Refinery as a 12 inch pipeline. It travels west through Apple Valley, then crosses the Minnesota River near the US-169 Bloomington Ferry Bridge. It travels north until it meets the BNSF Railroad line heading west towards the west coast. The pipeline follows the railroad to Willmar, Minnesota. At Willmar, the line branches, with a 12 inch pipe heading towards Fargo, and a second 12 inch pipe heading south. Just south of Willmar, the pipeline converts from a 12 inch pipe to an 8 inch pipe. The pipeline continues south to Granite Falls, then turns southwest to Marshall, Minnesota. The line branches at Marshall, with a 6 inch pipe heading to Watertown, South Dakota, and an 8 inch pipe heading to Sioux Falls, South Dakota. The Williams Brothers pipeline connects at several points to a network of 8,700 miles of pipeline carrying refined petroleum products connecting 13 states between Minnesota and Texas.
The Williams Brothers pipeline bridge is the only pipeline bridge that I am aware of in Minnesota. There is also a pipeline bridge on the Mississippi River new Cape Girardeau, Missouri, and at least 2 that I know of on the Missouri River. This is also one of the few pure suspension bridges located in the state of Minnesota.
The photo above is looking west across the Minnesota River along the north face of the pipeline bridge.