During the first half of 1916, Lassen Peak’s eruptions had greatly subsided since the major eruption of 1915. Then things changed suddenly. In August 1916, when Lassen became a national park, the peak began to perform again, as if the mountain’s reputation was at stake.
By fall, ashy mud began flowing in a steady stream from the crater of Lassen Peak and pouring into Manzanita Lake. This continued for several weeks. Lassen National Forest Ranger Fred Seaborn was so alarmed, that he stated if the flow continued at the rate experienced so far that Manzanita Lake would be obliterated within eighteen months. By November the mud flows stopped, as if someone turned off the spigot.