Around 10,000 years ago Glacial Lake Missoula filled western Montana’s valleys leaving pre-historic Missoula inundated by a few hundred meters of water. Silts and clays settling out of that lake left a 6-rn (20-ft) clayey silt (known locally as “clays”, but made up dominantly of rock-flour silt) veneer on the Missoula Basin. Clark Fork River and its tributaries subsequently have eroded most of these within the city limits, but extensive deposits are preserved west of town. A subtle terrace about 3.0 mi (4.8 km) west of downtown Missoula marks the eastern edge of the uneroded glacial rock-flour silts.

Brick making thrived between the 1880s and the 1920s, supplying Missoulas own building needs. Riddell & Watts brickyard, established in 1888 on the Northern Pacific line near the current airport, manufactured two to four million bricks per year during the building boom of the late 1880s and early 1890s. Brickmakers dug the glacial clays on the brickyard site. The bricks tend to be soft and porous owing to low firing temperatures, but builders understood the limitations and built with protection from weathering in mind. Many of those buildings remain well preserved to this day.

Plant production was drastically curtailed during the building bust of the middle 1890s. Prosperity returned by the late 1890’s, and Alfred Hollenbeck assumed management of the brickyard. Hollenbeck produced mostly common brick for Missoula buildings through the early teens.

For most purposes, Missoula builders found the locally-made common brick adequate, they commonly imported face brick from distant brickyards in places like Omaha, St. Louis, Spokane or Hebron, North Dakota. Missoula Brick and Tile Co. opened a brickyard in East Missoula in 1908 intending to produce face brick as well as common brick. The brickmakers apparently dug clays from the glacial clay deposits west of Missoula, but there also is evidence of pitting of Brickyard Hill, just west of Bandmann Bridge. The company indeed produced a fine variety of face brick for the local market through the middle 1920’s. Fred Sterling, a company co-owner, used the new bricks in building his own residence (1310 Gerald St., 1911), and it remains a well-preserved early example of his company’s bricks. Competition from other Montana brickyards, particularly Helena’s Western Clay Manufacturing Co. (Archie Bray Foundation), forced closure of the East Missoula brickyard by the middle 1920’s.