When was the last time Mount St. Helens erupted?
1980
1980
1980
1980
1980
1980
1980
1980
1980
1980
1980
1980
1980
1980
1980
1979
1980
1979
1980
1979
1990
1980
1979
1990
1980
1979
1905
1990
1980
1970
1979
1893
1990
1905
1980
1970
1989
1979
1893
1990
1981
1970
1905
1989
1986
1979
1985
1990
1981
1978
1893
1970
1908
1989
1986
1979
1905
1985
1990
1981
1982
1978
1970
1912
2021
1989
1987
1986
1979
1893
1980s
1908
1985
1883
1990
1991
1981
1982
1988
1978
1970
1989
1987
1986
1979
1912
2021
1985
1893
1990
1991
1980s
1981
1982
1988
1908
1978
1890
1970
1989
1987
1986
1983
1984
1979
1977
1985
1883
1912
1990
1991
1981
1907
2021
1982
1988
1978
1893
1970
1980s
1880
1908
1989
1987
1889
1986
1983
1984
1979
1890
1960
1977
1985
1990
1991
1902
1981
1982
1988
1978
1883
1970
1912
1907
2021
1989
1915
1987
1986
1983
1984
1979
1893
1980s
1960
1972
1880
1977
1985
1890
1990
1991
1981
1982
1988
1970
1902
1960
1907
1915
1893
1990
1889
1883
2021
1888
1902
1880
1915
1893
1980s
1895
1889
1883
1890
1855
1903
2021
1893
1880
1903
1904
1888
1872
1980s
1895
1891
1890
1893
1889
1886