As the twin ports of Duluth and Superior began to grow in their importance as ports, the quantity of vessel traffic making its way through this opening began to increase. In order to make passage safer, in 1856 the Lighthouse Board constructed a stone tower and keepers dwelling at the end of Minnesota Point for a total cost of $13,700.

After the channel was cut through Minnesota Point at the Duluth end in 1872 and the Duluth South Breakwater Light was established to mark the the new entry, maritime traffic bound for Duluth no longer needed to enter the harbor through the circuitous gap, and thus the opening began to be used solely for Superior traffic.

With the construction of protective timber piers at each side of the entry, a wood-framed pierhead beacon was erected on the end of the north pier in 1879, and exhibited for the first time on the night of September 1 of that year. With the Army Corps of Engineers continuing to dredge and enlarge the opening, the pierhead light was temporarily discontinued in 1880, and the old Minnesota Point light reactivated until work on the improved piers had progressed to a point that the pierhead beacon could be reestablished. This work was completed in 1885, and the pierhead beacon reestablished on the North Pierhead. With the establishment of this beacon, the old Minnesota Point Light was deactivated, and the dwelling refurbished to serve as quarters for the Keeper of the new light.

With the Army Engineer’s continuing to work on the piers, the decision was made to relocate the beacon across the channel to the longer south pier in 1892. After the beacon was transported across the channel and bolted in its new home, an elevated walk was erected from the beacon leading toward the shore to provide the Keeper with safe access to the light during stormy weather when waves washed across the surface of the pier. With the old Minnesota Point dwelling now inconveniently located on the opposite side of the channel, cost estimates and plans were also drawn up for the erection of a duplex keepers dwelling on the Wisconsin side of the entry. Also this year, the Lighthouse Board recommended the establishment of a fog signal on the south pier to serve as a guide to vessels making the entry at night and during thick weather, and requested an appropriation of $5,500 for its establishment.

1883 saw major changes at Superior entry with the arrival of a work crew at the site at the opening of the navigation season. Over the summer, the duplex dwelling with a six-room apartment on each side was built, and after erection of a boathouse, barn and 360-gallon capacity brick oil storage building, the buildings were connected with walkways and the station enclosed by a 200-foot by 200-foot picket fence.

That summer, work began on construction of a 20-foot by 40-foot steam fog signal building behind the beacon at the end of the south pier. A timber frame structure, its exterior walls were covered with corrugated iron sheets, and the inner walls with smooth iron sheeting. Within the building, a pair of locomotive-style steam boilers were installed and plumbed into a pair of 6-inch Scotch whistles, which were mounted on the iron roof of the structure. After the elevated walkway was connected to the fog signal building and extended an additional 100 feet toward the shore, work on the fog signal was completed and the signal placed in operation on August 27, 1893. It would appear that the new fog signal was indeed a valuable enhancement to navigation, as two years after its establishment, the keepers toiled to feed 44 tons of coal into the hungry boilers to keep the whistles screaming their warning across Superior for a station record 895 hours.

In 1898, the decision was made to add a second light on the south pier to serve as a rear range to the pierhead beacon to help mariners locate the course into the channel. With work underway at the Devils Island light station to replace the temporary timber-framed beacon on the island with a permanent iron structure, plans were put in place to move the old beacon to Superior Entry to serve as the new rear beacon. However, with the lens for the new Devils Island tower unavailable, and delaying the availability of that structure, a temporary post was erected on the south pier 1,650 feet behind the pierhead light, and exhibited for the first time on the night of November 30, 1897.

With the installation of the lens in the iron tower on Devils Island late in the summer of 1901, the old timber beacon was removed from the island and shipped to Superior. On erection on the south pier, the lantern was outfitted with a fixed white Fourth Order Fresnel lens. With the work completed close to the end of the navigation season, the new rear range light was not exhibited from the relocated structure until the opening of the 1902 navigation season on April 1, 1902.

The Army Corps of Engineers were back at work at Superior Entry in 1905, erecting new concrete piers to the outside of the old timber structures. With plans to remove the old piers on their completion, it was clear that the existing front range on the pierhead, fog signal and rear range would need to be relocated to the new concrete piers on their completion. Estimating the cost of erecting new structures on the concrete piers to be $20,000, the Lighthouse Board requested an appropriation of that amount in its annual report for 1905, and began working on plans and specifications for the new structures. As is all too frequently the case, the greatest of man’s plans stood like twigs in the face of Mother Nature’s fury when a violent storm swept across Lake Superior on November 27. By the time the storm had abated the following day, the Superior Entry Keepers were faced with an incredible scene of devastation. Waves smashing across the pier had snapped the 12-inch timbers of the front beacon like matchsticks, completely carrying the structure away, along with 250 feet of the elevated walk. The roof and upper two thirds of the fog signal building were completely gone, along with 40 tons of coal which had been swept from the hopper. Repair work began immediately with the temporary rebuilding of the fog signal building, and the erection of a temporary frame lantern installed atop the structure’s roof. However, with winter putting an end to the work, the fog signal and light were not reactivated until April 15 of the following year.

Congress responded to the previous year’s request with an appropriation of $20,000 on June 30, 1906, however with the Army Corps of Engineers still working on the new concrete piers, the construction was postponed pending the completion of the new structures. By 1910, the Corps of Engineers had revised their plans for Superior Entry, deciding to construct two long concrete arrowhead breakwaters outside of the piers in order to create a large stilling basin. With these enhancements, the newly formed Lighthouse Establishment was forced to rethink its plan for lighting the harbor entry. Determining that it would be best to erect the fog signal and main entry light at the end of the South Breakwater and to establish unmanned acetylene beacons on the piers, it estimated that the total cost of construction would now reach $45,000, which was $25,000 beyond the Congressional appropriation of 1906, and requested a second appropriation of $25,000. Congress responded with the requested secondary appropriation on March 4, 1911, and preliminary plans for the structures were drawn up and approved soon thereafter, and by July, the Army Corps of Engineers had completed work on the 11 ½ foot high concrete base for the new South Breakwater Pierhead light. Contracts for construction were awarded on June 30, 1912, and construction began almost immediately.

The concrete foundation for the Main Light and fog signal contained vaulted cellar rooms for the storage of oil and paint, along with a large tank for drinking water. Atop this foundation, the main structure took the shape of an oblong two-story reinforced concrete building with rounded ends. Structural steel framing within the building carried concrete floors, and all interior walls were lined with plaster-finished terra cotta tile. Inner partition walls were of expanded metal with a smooth coating of plaster, and the stairs between the decks of cast iron. The first deck served as a mechanical room, housing a pair of compressors powered by 22-horsepower inline gasoline engines to supply air to the fog signal, a steam heating plant, toilet and cold storage areas. The second floor made up the living quarters, with a kitchen, living room, three bedrooms and a bathroom. The circular tower rose through the sheet metal roof at the offshore end of the building, with a spiral stairway leading from the second floor. The circular tower protruded from the offshore end of the building, and featured two floors, the lowest of which housed a pair of six-inch air sirens with their resonators protruding out the wall, and the second serving as a service room. Atop the service room, a copper-roofed circular lantern room with helical astragals, housed a fixed Fourth Order Fresnel with a rotating screen within the lens. Mounted on ball bearings and driven by a clockwork motor, the screen rotated around the lamp imparting a repeated isophase occulting characteristic of 5 seconds of light followed by 5 seconds of darkness. Sitting 70 feet above lake level, the 2,900 candlepower lamp was thus visible for a distance of 16 miles in clear weather.

On establishment of the new lights, the old South Pierhead range and fog signal were discontinued, and the structures demolished.

The air siren equipment was removed from the tower in 1937, and a Type F diaphone fog signal installed, and the following year a radiobeacon was installed at the station.