Lanyon is an unincorporated community in Lost Grove Township in Webster County, Iowa. It is located 17 miles south of the county seat of Fort Dodge, 2.65 miles south and one mile west of Harcourt, and 3.3 miles north and 4.5 miles west of Boxholm. Lanyon consists of seven blocks, bounded on the north by 390th Street, and on the east by Lanyon Av…Lanyon is an unincorporated community in Lost Grove Township in Webster County, Iowa. It is located 17 miles south of the county seat of Fort Dodge, 2.65 miles south and one mile west of Harcourt, and 3.3 miles north and 4.5 miles west of Boxholm. Lanyon consists of seven blocks, bounded on the north by 390th Street, and on the east by Lanyon Avenue.