James Arthur Mathieu (August 21, 1869 – November 23, 1966) was known as "the last of the lumber kings,"^[1] as well as "the Mighty Man of the Woods" and "the Lath King of America."^[2] Born in Alma, Wisconsin.,^[3] he became an Ontario lumber merchant, philanthropist and political figure. He represented Rainy River in the Legislative Assembly of Ontario initially as a Liberal-Conservative in 1911, and then as a Conservative from 1914 to 1923 and 1926 to 1929.

Having worked in his youth as a log driver on the Mississippi River,^[1] Mathieu came to Rainy River from Minnesota around 1903 as a manager of the Rainy River Lumber Company's sawmill, later becoming manager and vice-president at the Shevlin-Clarke Company.^[4] He was later involved in controversy as part of what became known as the "Old Tory Timber Ring,"^[5] when fellow Conservative Howard Ferguson, as Minister of Lands and Forests, arranged for the sale of three timber limits in the Quetico Forest Reserve to Shevlin-Clarke for less than half the price they would have normally fetched,^[6] and the company later paid a fine of $1.5 million for breaching the Crown Timber Act.^[7] The transactions were criticized in a subsequent inquiry.^[8]

In 1921, he left Shevlin-Clarke and founded J.A. Mathieu Limited, which set up a mill at Rainy Lake.^[9] The company opened another sawmill in 1945 at Sapawe Lake, near Atikokan.^[10][11] He was instrumental in pioneering the use of mechanized equipment in the woods (while other firms were still relying mainly on horses), as well as in using aircraft.^[12] After his death, the company was acquired by Domtar.^[11]

He set up an educational foundation to provide financial assistance for students from the area,^[12] for which he was honoured in 1958 by the Ontario Secondary School Teachers Federation.^[2] Mathieu also established a wildlife reserve and help fund community projects in the region.^[12] During his time in the provincial assembly, he helped promote the development of roads to encourage settlement in the district.^[12] He also served as President of the Northern Pine Manufacturers Association for 22 years.^[2]