Complex sentence: The highway exists entirely as a part of the Kansas Turnpike, and this stretch of the Turnpike was in fact for 31 years (from the opening of the Kansas Turnpike in 1956 until 1987) designated solely as the Kansas Turnpike without an interstate number.
Split into simpler sentences: The highway exists entirely as a part of the Kansas Turnpike. This stretch of the Turnpike was for 31 years (from the opening of the Kansas Turnpike in 1956 until 1987) designated solely as the Kansas Turnpike without an interstate number.