Complex sentence: Riley had a peripatetic youth and spent his first 11 + years in northern Idaho, but he considers the college town of Corvallis his hometown after he arrived in the spring of 1965, near the end of sixth grade, and stayed through high school.
Split into simpler sentences: Riley had a peripatetic youth and spent his first 11 + years in northern Idaho, but considers Corvallis his hometown. He arrived in the spring of 1965, near the end of sixth grade, and stayed through high school.