When was the last eruption of Mt. St. Helens?
18-May-80
1980
1980
1980
1980
1980
1980
1980
1980
1980
1893
1980
1980
1893
1979
1980
1990
1979
1893
1883
2100 BC
1905
1890
1980
1990
1979
1908
1893
1980
1890
1880
1990
1970
1979
1883
1902
1980s
1905
1980
1700
1893
1990
1970
1979
1981
1908
1980
2200 BC
1883
1902
1980s
1905
1890
1880
1989
1889
1990
1700
2300 BC
1970
1979
1912
1893
1981
1980
1907
1991
1908
1989
1990
1883
1902
1985
1970
1979
1905
1890
1880
1700
1981
1978
1912
2400 BC
1986
1893
1980
1700 BC
2100 AD
1980s
1991
1989
1889
1990
1985
1970
1979
1907
1908
1981
1883
1902
1982
1905
1978
1890
1986
1880
1980
1700
1912
1991
1893
1989
2021
1990
1985
1980s
1970
1979
1700 BC
1855
1889
1981
1907
1908
1980
1988
1902
1905
1991
1880
1990
1700
1700 AD
1912
1893
1883
1980s
1890
1889
1895
1700 BC
1891
1907
1908
1879
2021
1904
1902
1905
1915
1903
1880
1700
1912
1893
1883
1980s
1896
1890
1888
1855
1889
1895
1700 AD
1907
2021
1904
1915
1903
1891
2021
1904
1915
1903
1880
1700 AD
1860
1893
1879
1886
1897
1883
1980s
1896
1890
1888
1855
1700.
1889
1895
1891
1880 AD
1880
2100
1880s
1700.
1872
1893
1879
1886