Interstate 99, often abbreviated as I-99, is a highway in the United States that runs through the states of Pennsylvania and West Virginia. It connects the cities of Altoona and State College in Pennsylvania, providing a vital route for both local and long-distance travel. The highway is approximately 90 miles long and serves as an important corridor for commerce and tourism in the region. I-99 is part of the larger Interstate Highway System, which includes major highways across the country. It was designated in the late 1990s and has since been a key route for residents and visitors, facilitating access to various attractions, including Penn State University and the scenic Allegheny Mountains.