Split Rock Lighthouse is an octagonal, brick light in the Iron Range region of Minnesota. Ralph Russel Tinkham created the picturesque design. It became operational in 1910. For almost 60 years, the rotating beacon could be seen up to 22 miles away in Lake Superior thanks to the vigilant keepers. They had to crank the 6.5 ton lens weights every two hours while also maintaining adequate kerosene levels. In 1940, Split Rock was fitted with a 1000 watt bulb. This scenic lighthouse and ten adjacent buildings are one of the most visited parks in the state.