Strong high-altitude winds carried material east-northeasterly from the Plinian column to as far as Alberta, away from the vent to produce a large volcanic ash deposit. This widespread ash deposit, known as the Bridge River Ash, overlies older ash deposits from other large explosive eruptions in the Cascade Volcanic Arc, such as the 3,400‑year‑old Yn Ash from Mount St. Helens and the 6,800‑year‑old Mazama Ash from the catastrophic collapse of Mount Mazama. After this took place, a major pyroclastic flow deposited blocks of rounded pumice to in diameter on pyroclastic fall deposits of the collapsed Plinian column. The pyroclastic flow burnt and buried Meager's forested slopes in place. Remnants of this catastrophe are exposed south and east of the Bridge River Vent along the Lillooet River. At the vent area, the thickness of this pyroclastic flow ranges from to .