Consists of photographs of particularly mining development in Northwestern Ontario in the late 19th and early 20th centuries, as well as the waterfront and shipping, local scenery, and notable figures. Also includes some correspondence; railway construction plans.

Records relating to Daniel John "Jack" Coghlan (1934-2018), early professional diver born in Fort William. He began his career in the Thunder Bay region and later worked around the world, living in California, Australia, Alaska, and Hawaii.

The collection consists of digital copies of photographs, news articles, and documents, as well as written stories contributed by family and friends. Articles relate to Coghlan's career as a salvage diver (Superior Diving & Salvaging Co.) including attempts to salvage the Gunilda and other shipwrecks. Through this era, he was frequently referred to as a "frog man" in news articles. In later years he worked supporting offshore oil development.

The collection was assembled by Sam Coghlan, Jack's brother.

Two documents containing transcriptions and images of the Silver Islet Cemetery:
"Silver Islet Cemetery," Ontario Genealogical Society, 1982
"Silver Islet Cemetery," 2007.

Photographs and documents from the Silver Islet Mine and Silver Islet Store, including ledgers and a chart.

A rich deposit of silver was discovered on Silver Islet in 1868. A small island at the tip of the Sibley Peninsula, the mine was built deep below the waterline, and relied on breakwaters and pumps. Silver Islet was mined until 1884, when pumps failed, and the mine was flooded. The small community built on shore to support the mine is still inhabited.