Houghton and Hancock Michigan
Houghton and Hancock are essentially twin cities, sitting across the Keweenaw Waterway/Portage Lake from each other. They are the urban centers of the Keweenaw Peninsula and a nice place to stop if you're exploring the area. Both began growing in the 1840s and 1850s and were substantial towns by the end of the 1800s. The region's copper mines and copper processing facilities initially fueled both towns' growth. The Quincy Smelter is just East of Hancock and the Quincy Mine is just North. The 10 mile drive from Hancock to Lake Linden on highway 26 passes multiple former industrial sites including the Quincy Stamp Mill and Ahmeek Stamp Mill ruins. Both Houghton and Hancock have nice central business districts with shops, stores and restaurants in beautiful 19th century buildings. Houghton is the home of the Michigan Technological University which has the only industrial archeology program in the United States. I think this must contribute to the remarkably active and successful preservation community in the Keweenaw.
Hancock's population peaked at 8,918 in 1910. It's current population is 4,634. After loosing residents for most of the 20th century Hancock's population has stabilized and is now slowly growing. Houghton was slightly smaller than Hancock during the copper mining boom in the late 1800s and early 1900s. It's population was 5,113 in 1910. It is now the larger of the two cities with 7,708 residents.