March 15, 1980: Seismic activity begins with an increasing number of earthquakes.
March 20: A magnitude 4.2 quake is the first substantial indication of St. Helens' reawakening after 123 years.
March 27: First significant eruption in the "Lower 48" since California's Lassen Peak (1914-1917) opens a 250-foot crater.
April 30: Gov. Dixy Lee Ray, who had proclaimed a state of emergency on April 3, orders a Red Zone barring the public from areas around the volcano.
May 18: Eruption at 8:32 a.m. claims 57 lives and obliterates virtually everything within 8 miles.
May 19: Interstate 5 remains closed near Castle Rock because of fears Toutle River bridge is damaged.
May 20: Eastern Washington digs out from under an ash blizzard. Seattle and Portland send 50 trucks and sweepers to help Yakima clean an estimated 600,000 tons of ash. Spokane, which had 5 inches in spots, rations water as people hose the ash away.
May 21: Then-President Jimmy Carter arrives in Vancouver with several cabinet secretaries and members of Congress.
May 22: After seeing the damage from a helicopter, Carter says, "The moon looks like a golf course compared to what's up there."
May 23: With squad cars ruined by ash, Moses Lake police patrol on bikes; Yakima fruit growers use helicopters to blow ash off trees.
May 25: Emergency officials say 10,000 to 15,000 people were stranded when ash halted air, rail and highway travel in the state.
May 27: Nine days after the blast, the number of known dead stands at 21, with 68 missing.