Illinois Route 120 is a state highway located in northern Illinois. It runs approximately 30 miles, connecting the cities of Grayslake and McHenry. The route primarily serves as a vital east-west corridor, facilitating local traffic and providing access to various communities along the way. The highway passes through several notable areas, including Lake County and McHenry County. It intersects with other major roads, enhancing connectivity for residents and visitors. Illinois Route 120 is essential for commuters and supports local businesses by linking them to larger transportation networks.