Weiser, Peter M., mountain main (Oct. 3, 1781-c. 1810). Born in Berks County, Pennsylvania, he joined the Lewis and Clark expedition probably late in 1803, accompanying it to the Pacific and return. In 1807 he signed on with Lisa, reached the Three Forks area and ascended the Madison River. Weiser may have guided Henry to Henry's Fork of the Snake River in 1810. He presumably was killed by Blackfeet about that time; he assuredly was dead by 1825. Weiser, Idaho, and the Weiser River are named for him.