Terry Pepper’s Seeing the Light is my go-to for Michigan lighthouse lore. His entry for the Keweenaw Upper Entrance Lighthouse says in part:
With the meteoric growth of copper mining in the Keweenaw between 1843 and 1968, increased shipping access to the twin cities of Houghton and Hancock became increasingly important. To this end, the Portage River Canal was cut through a tamarack swamp at its western end in 1860, creating a channel 10 feet deep and 80 feet wide, opening full Portage River navigation for the largest vessels of the day from western Lake Superior.
In 1874, to assist in safely guiding ships into this cut, a large gabled two-story brick dwelling with attached square 33 foot high brick tower was constructed on the west bank at the entrance to the canal. With increasing use of the canal, silting became a major problem, and tolls were levied for its use in order to cover the continuing expenses for repairs and dredging.
For reasons as yet undetermined, the original lighthouse was replaced with the existing fifty foot square steel Art Deco style tower at the end of the breakwater in 1950.