Brief notices in books and old newspapers report eruptions from Mount Rainier on at least fourteen dates between 1820 and 1894. Descriptions of the supposed eruptive activity are vague, however, and in no case is there a clear record of the emission of new lava or ash. Recent mapping of the geology of Mount Rainier National Park brought forth no geologic evidence to substantiate such recent activity. The youngest blanket of pumice and ash from Mount Rainier consists of two or more distinct ash falls. Both tree-ring and radiocarbon methods of dating indicate that it was deposited about 550-600 years ago. Mount Saint Helens, on the other hand, was in eruption more recently. Historic accounts of eruptions from this volcano in 1831, 1842, and 1843 appear to be reliably documented, and there is also geologic evidence of very recent activity.