NF-790 is a unimproved logging trail that loops off of and back onto Moose Line Road in the southeastern part of the Superior National Forest. The bridge is located at a former logging dam. The road was built to service the dam. At the current time, the northern section of the road is passable by 4 wheel drive vehicles when it is dry. The southern section is closed to motorized vehicles other than ATVs. The bridge is mostly designed for ATV traffic. There is a large gate installed about 400 feet north of the bridge, with opening at each end wide enough for an ATV to pass through.

A logging dam was typically built by making a square wooden crib, which was placed in the river and filled with rocks. Boards could be placed between two cribs to make a sluice gate. The dam would store up water for a few weeks, and then open to allow a slug of water and a group of logs to head down river. The slug of water would carry the logs over rapids and through shallow spots. To make the logs easy to handle, they would be pulled (or skidded) using teams of ox or horses. The animals would pull groups of logs onto the ice during the winter. In spring, the ice would melt, dumping the logs into the water ready to be sent downriver.

The bridge is built with steel girder beams strung between the abutments. A wood deck is then put down and attached to the girders. Every so often, a much longer deck board is installed. That longer deck board is used to cross-brace the railings giving them some side to side support.

It appears that the ATV bridge is relatively new. I suspect that the old logging dam supported a bigger bridge that allowed for vehicle traffic. Over time, that bridge would have rotted and became unsafe. At some recent time, the bridge and dam were removed, the rocks were used to build up the embankment, and this trail bridge was installed.