New Plymouth is a city in Payette County, Idaho. The population was 1,538 at the 2010 census, up from 1400 in 2000. It was incorporated on February 15, 1896. It is the host of the annual Payette County Fair and rodeo. New Plymouth is part of the Ontario, OR–ID Micropolitan Statistical Area. History New Plymouth was a colony town, bought and planned before it was settled. It was the combined project of a group of people purportedly dissatisfied with city life in Chicago, who in 1895 formed what they called "The Plymouth Society of Chicago" and William E. Smythe, who was the chairman of the executive committee of the National Irrigation Congress and a famous irrigation promoter. Mr. Smythe was determined to found a colony to serve as a striking argument in favor of his project - irrigation. He spoke throughout the east, urging young and old men to go west in colonies and develop the country with the help of irrigation. He wanted the first colony to be called New Plymouth — after Plymouth, Massachusetts — and wanted it located in southwestern Idaho in the Payette Valley, which he had found apt for his purpose because of the extraordinary water supply via the nearby Payette River. The Plymouth Society of Chicago selected a committee to investigate the irrigated Payette River Valley in the five-year-old state of Idaho, and another site in Colorado, to be purchased for the colony. The present city of New Plymouth was on the drawing boards in Chicago, designed as a town able to be self-reliant through the use of irrigation, solidly built on an agricultural and railroad economy. In February 1896, each colonist purchased 20 shares of stock at $30 per share, which entitled him to of land and a town lot. He was to clear the land of sagebrush and plant fruit trees, preferably apples. The town was platted with a horseshoe shape with its open end facing to the north, toward the railroad and the river. This area was planned as an industrial zone, and the acre tracts around the horseshoe were the residential lots. The homes were to be built on the street side and the balance of the acre for garden and pasture for the family cow and the driving team. Two streets, separated by an park, curve around the town in a horseshoe shape. This mile-long (1.6 km) park and