Word spread of Tifft’s "discovery" of the bounty of Lake Betsie, and a number of "easterners began buying land around the lake. With harbor improvements key to the area’s growth, private interests undertook the first harbor improvement in 1859, spending $16,000 to dredge a channel between two short piers at the river mouth.

With these initial improvements, Frankfort became the most northerly improved harbor on the eastern shore of Lake Michigan. With vessels making the Manitou Passage less than five miles offshore, the harbor soon became an ideal and frequently used harbor of refuge. Reflecting the harbor’s growing importance, Ohio Senator State Benjamin Franklin Wade presented a memorial praying for improvements to the harbor before the Senate on behalf of the Detroit Board of Trade and a number of Michigan ship owners on March 14, 1864. While the matter was referred to the Committee on Commerce for consideration, Wade continued to press the issue, presenting further memorials over the following month on behalf of maritime interests from Toledo to Milwaukee.

Concurring with the growing importance of the harbor, Congress dispatched the Army Corps of Engineers to Frankfort to begin improvements on July 1, 1867. Plans for the new harbor called for the cutting of a new channel approximately seven hundred and fifty feet to the south of the natural outlet. This opening was then to be dredged to a width of two hundred feet and an overall depth of twelve feet. Protected by a pair of parallel piers and revetments, Lake Betsie would thus be opened-up to the largest vessels of the day. As harbor improvements progressed, Eleventh Lighthouse District Engineer General Orlando M Poe noted in his 1871 annual report that funding would be required in order to establish a pierhead beacon to guide mariners into the harbor on the project’s completion. With completion of the piers in 1873, plans for the new light station were well underway. John H King was appointed to the position of Acting Keeper of the Frankfort Pierhead Light on May 9 of that year. While a keeper’s dwelling was normally considered a vital component of such a new station, the appropriation requested for the establishment of the new Frankfort light station did not include sufficient funds to erect a keeper’s dwelling, and thus King was forced to rent accommodations in town.

Materials for the erection of the new beacon were delivered to Frankfort soon after King’s arrival, and it is likely that he worked as part of the construction crew throughout that summer. The new light took the form of an enclosed timber-framed pyramid beacon with a square gallery located at the outer end of the South Pier. Centered atop the gallery, an octagonal iron lantern housed a fixed red Sixth Order Fresnel lens, and an enclosed service room below the gallery provided both a work area and a place to escape bad weather when working on the light. The structure’s location atop the pier was designed to place the lens at a focal plane of 25 feet, with a visible range of almost twelve miles during clear weather. An elevated timber walkway stretched along the center of the pier from the shore to a door in the service room wall, to allow keepers to travel safely above the waves that frequently crashed over the surface of the pier. Work on the beacon and walkway were completed late that fall, and Keeper King made his way along the walkway to exhibit the new Frankfort South Pierhead Light for the first time on the night of October 15, 1873.

With the Corps of Engineers returning to undertake continued improvements in the harbor, the South Pier was lengthened an additional 200 feet in 1884. While the work was underway, a violent storm swept through the area, and waves crashing across the pier destroyed 90 feet of the elevated walkway, and severely damaged an additional 170 feet. A crew was dispatched to Frankfort to effect the necessary repairs, and while at the site, they also erected a wood-framed oil storage shed and boat hoist at the inner end of the pier to allow the keeper to hoist his boat onto the pier deck. Before the end of the season, the beacon was lifted and moved 195 feet along the pier to the new pierhead. That winter, the schooner AMSDEN was entering the harbor under tow when she parted her tow line, and ran her bowsprit through 32 feet of the elevated walk. Keeper Albert Vorce hired a local work crew, and personally directed the necessary repairs.

In order to make the station effective during thick weather, Eleventh District Engineer Major William Ludlow proposed that a fog signal be added to the station. Estimating that a timber pyramid structure similar to the existing beacon could be erected and outfitted with a fog bell and striking apparatus in storage in the Detroit depot for only $1,000, a request for the necessary funds was made in 1891. Congress responded with the requested appropriation on August 5, 1892, and work on the new structure began on April 14 of the following year. A timber framed pyramid tower, similar in appearance to the beacon was erected 8 feet to the rear of the existing structure. Standing 10 feet by 16 feet in plan, the lower section of the tower was enclosed to house the striking apparatus, and the bell suspended in the upper section, which was left open to allow the sound of the bell to carry in all directions. A covered walkway was erected between the two structures to provide shelter when passing between the two buildings. On completion, both structures and the connecting walkway were given a fresh coat of white paint.

In January 1893, the Toledo, Ann Arbor and North Michigan Railroad began operating a pair of railroad car ferries between Frankfort and Kewaunee, Wisconsin. With car ferry service also added to Menominee, Manistique and Manitowoc in 1896, the commercial importance of the Frankfort harbor increased dramatically as Midwest industry began to rely on rail traffic passing through the harbor. To better serve the car ferries, the Army Corps of Engineers again extended the Frankfort piers in 1896. With completion of this extension, new foundations were erected on the new south pierhead onto which both the pierhead light and fog bell building were lifted and moved on November 16. With this move, 600 feet of elevated walk was also rebuilt, allowing the keepers to safely travel the full length of the extended pier. To simplify locating the opening between the piers, a second light was installed on the South pier on January 22, 1897. Consisting of a lens lantern atop a 60 foot tall steel post located 600 feet to the rear of the pierhead, the new light was designed to serve as a rear range to the pierhead light.

After experiencing frequent problems with the old fog apparatus, the fog signal machinery from Chicago, which was being replaced by a steam operated fog signal plant, was shipped to the depot in St. Joseph for refurbishment in 1898, and installed at Frankfort the following year. However, after continuing problems were experienced with the replacement mechanism, the decision was made to install an air operated siren at the station in 1900. To this end, a 2-horsepower diesel engine was installed in the enclosed lower section of bell tower alongside the fog bell apparatus and connected to a siren and copper trumpet which were installed on the exterior of the building. Installation of the new fog signal apparatus was completed on May 1, 1901. By the end of July, foggy weather conditions caused the new signal to be activated for a total of 54 hours, during which it proved itself to be a vast improvement over the old system.

With the dawning of the twentieth century, arrangements had still not been made to erect a permanent dwelling at Frankfort, and keepers assigned to the station were forced to continue renting living quarters in town. In an attempt to correct the situation, Ninth District Inspector Commander Lucien Young requested an appropriation of $6,500 for the erection of a duplex dwelling for the station’s keepers. After a backup 2-horsepower engine for the fog signal was installed in 1905, the old fog bell equipment was removed and shipped to the St. Joseph depot for storage.

Evidently, the funds for erecting a keeper’s dwelling were finally approved, as 1907 saw the commencement of condemnation proceedings on a parcel of land selected for the new dwelling. To this point, we have been unable to identify definitively whether the much needed dwelling was ever built. However, the 1910 annual report of the Lighthouse Bureau reports that bids were solicited for the erection of a brick oil storage building at the station. Since such a brick structure would necessarily have to be built on land, it is likely that it was built on the same land on which a dwelling was finally erected.

1912 saw significant a significant change in the lighting of the Frankfort harbor entrance. A new square steel pyramidal tower was erected on the North Pier. Fully sheathed in steel plates, the white painted structure stood 44 feet from its base to the top of the ventilator ball. Outfitted with a fixed red Fourth Order Fresnel lens, the tower’s location on the north pier provided the new light with a focal plane of 46 feet, and a visible range of 12 miles in clear weather. The air siren from the South Pierhead light was relocated into this new structure, and set up to emit a characteristic isophase characteristic of alternating periods of 3 second blasts and 3 seconds of silence. An elevated walkway, similar to that installed on the south Pier, was erected from the new light to the shore.

The lens lantern from the South Pier rear range light was moved to a 66-foot tall wooden post erected 200 yards behind the new light on the north pier. The old South Pierhead Light and fog signal were then both demolished, and replaced with an acetylene powered lens lantern on a 35-foot tall open-framed pyramid structure 15 yards from the end of the south pier.

With the electrification of the town, a supply of inexpensive and reliable electricity became available, and the Frankfort pierhead lights were electrified in 1919. With electrification, the output of the North Pier Front Light was increased to 1,900 candlepower, and a resulting increase in visibility range to 14 miles, and the rear light to 740 candlepower. The fog signal in the North Pier Light was also changed to an electric air compressor-driven diaphone sounding a single two-second blast every 20 seconds. The old diesel engine powered siren was left in place to serve as a backup in the case of failure of the electricity or the diaphone equipment.

By 1924, the total car ferry tonnage through Frankfort Harbor was twenty five times greater than that prior to the establishment of the ferries. To better serve this vital commerce, the Army Corps of Engineers began construction of a pair of reinforced concrete arrowhead-type breakwaters at the harbor entrance in order to create a large stilling basin to protect the opening into the harbor. With the completion of these breakwaters in the early 1930’s, the twin piers at the entry into Lake Betsie no longer served any purpose. With plans in place to shorten them into short stub piers, the North Pierhead Light was lifted from the pier onto the deck of a barge and carried out to the end of the North Breakwater. A square steel base 25 feet in height had been erected on the end of the breakwater to receive it, and the tower was lifted onto the new base. After being bolted into position, the new tower stood 67 feet in height from the upper level of the pier to the top of the lantern ventilator ball. By virtue of its location on the concrete pier, the light stood at a focal plane of 72 feet, and the 17,000 candlepower incandescent electric light within the Fourth Order Fresnel was visible for a distance of 16 miles in clear weather.