Lewis Evans (1700 - June 11, 1756) was a Welsh born American naturalist, surveyor, and geographer active in Philadelphia and the Ohio Valley in the first half of the 18th century. He was born in Llangwnadl, Carnarvonshire, Wales - a fact which he revealed in his will. Otherwise, little is known of his early life. He had a classical education in England and from his own writings it is hinted that he traveled extensively abroad, as far as India and South America, before settling in Philadelphia. The first mention of Evans is his purchase of Edward Cocker's Arithmetick at Benjamin Franklin's Philadelphia bookshop on November 27, 1736, so he must have immigrated to the colonies sometime before this. From the earliest available records, it is evident he trucked elite intellectual circles, befriending, and even working with Benjamin Franklin, Cadwallader Colden (1688 - 1776), Thomas Pownall (1722 - 1805), Thomas Penn (1702 - 1775), among many others. He lectured throughout Pennsylvania on the wonders of electricity, of which he reportedly had a firm grasp. His cartographic corpus is small but significant. Other than several minor survey maps focusing on holdings in eastern Pennsylvania, Evans's published only two major maps, A Map of Pennsylvania, New Jersey, New York, and the Three Delaware Counties (1752) and A General Map of the Middle British Colonies in America (1755), the latter being a most significant and a landmark production focusing on Trans-Appalachia. It is noteworthy that Evans was a meticulous cartographer and, unlike most mapmakers of this period, based his maps an actual survey work which he personally conducted. Evans died in Philadelphia on June 11, 1756, one year after his greatest work was published. His body lies in the Christ Church Burial Ground in Philadelphia. After his death, his only daughter Amelia was brought up by Deborah and Benjamin Franklin.