and before that?
Between 1980s to 1991
1980 eruption of Mount St. Helens
An eruption occurred on May 25, 1980, at 2:30 a.m. that sent an ash column into the atmosphere. The eruption was preceded by a sudden increase in earthquake activity and occurred during a rainstorm. Erratic wind from the storm carried ash from the eruption to the south and west, lightly dusting large parts of western Washington and Oregon. Pyroclastic flows exited the northern breach and covered avalanche debris, lahars and other pyroclastic flows deposited by the May 18 eruption.

At 7:05 p.m. on June 12, a plume of ash billowed above the volcano. At 9:09 p.m. a much stronger explosion sent an ash column about skyward. This event caused the Portland area, previously spared by wind direction, to be thinly coated with ash in the middle of the annual Rose Festival.
A dacite dome then oozed into existence on the crater floor, growing to a height of and a width of within a week.

A series of large explosions on July 22 broke more than a month of relative quiet. The July eruptive episode wa
what happened after the mt st helens eruption An earthquake which caused the entire weakened north face to slide away, creating the largest landslide recorded when was the last time it erupted? January 2008 and before that? October 2004
wiki:20190521
1980 eruption of Mount St. Helens [SEP] 1980–1991
An eruption occurred on May 25, 1980, at 2:30 a.m. that sent an ash column into the atmosphere. The eruption was preceded by a sudden increase in earthquake activity and occurred during a rainstorm. Erratic wind from the storm carried ash from the eruption to the south and west, lightly dusting large parts of western Washington and Oregon. Pyroclastic flows exited the northern breach and covered avalanche debris, lahars and other pyroclastic flows deposited by the May 18 eruption. At 7:05 p.m. on June 12, a plume of ash billowed above the volcano. At 9:09 p.m. a much stronger explosion sent an ash column about skyward.