Lemhi is an unincorporated place in Lemhi County, Idaho, United States. Lemhi is located along Idaho State Highway 28 and the Lemhi River, 8 miles south of Tendoy and 18 miles northwest of Leadore. Lemhi consists of a combined general store and post office and a house. The post office services ZIP code 83465. As with the county, the name "Lemhi" is a …Lemhi is an unincorporated place in Lemhi County, Idaho, United States. Lemhi is located along Idaho State Highway 28 and the Lemhi River, 8 miles south of Tendoy and 18 miles northwest of Leadore. Lemhi consists of a combined general store and post office and a house. The post office services ZIP code 83465. As with the county, the name "Lemhi" is a variant spelling of Limhi, a personage of the Book of Mormon.