The 775 area code covers the entire state of Nevada, excluding the Las Vegas metropolitan area (which uses the 702 and 725 area codes). As Nevada is a large, sparsely populated state, the 775 area code serves a wide geographical region, including cities like Reno, Carson City, and Elko, as well as numerous smaller towns and rural communities. It's important to note that while it serves these cities, it encompasses the entire northern and rural parts of the state.