In the 1885–1886, the
North Pacific Coast Railroad (NWP) extended its
narrow-gauge line up Austin Creek to transport lumber from Cazadero to points south. Sonoma Magnesite Company was formed in 1912 to mine the
Red Slide Deposit of
magnesite in The Cedars. The mineral is important for steel-making and manufacture of bricks for high-temperature applications; but cost of transportation made mining in The Cedars infeasible until
World War I interrupted availability of less expensive sources. The Sonoma Magnesite Tramway, an eleven-mile-long, narrow gauge
industrial railway was built in 1914 along the bank of East Austin Creek to connect the mine with Magnesia station on the NWP railroad south of Cazadero. Thirty tons of ore were calcined daily in an oil-fired rotary kiln and packed into sacks for shipping. Production ended in 1920 when magnesite again became available from less expensive sources.
Sonoma Magnesite Tramway The railway shipped sacks of magnesite on 4-wheel
flatcars. Each of the ten flatcars was four feet wide by seven feet long and could be loaded with 5 tons of magnesite. Oil for the kiln was shipped in six 500-gallon
tank cars eight feet long. Trains were pulled by an unusual variety of locomotives: High water in East Austin Creek washed out significant portions of the tramway in 1921; and
Betsy was washed downstream and partially buried in the gravel channel. Most of the rails had been salvaged by 1925; and
Betsy was converted to scrap metal in 1961. ==Habitat and pollution==