Complex sentence: The Sperry Chalet was built in 1913 by workers employed by the Great Northern Railway and is listed as on the National Register of Historic Places and was part of the Great Northern Railway Buildings that have been listed as a National Historic Landmark.
Split into simpler sentences: The Sperry Chalet was built in 1913 by workers employed by the Great Northern Railway and is listed as on the National Register of Historic Places. It was part of the Great Northern Railway Buildings that have been listed as a National Historic Landmark.