The city of Alamosa is a Home Rule Municipality that is the county seat and the most populous city of Alamosa County, Colorado. The census 2005 estimated that the city population was 8,682. The city is the commercial center of the San Luis Valley in south-central Colorado. Alamosa is now a notable tourist town with nearby attractions including the Great Sand Dunes National Park and Preserve and Colorado Gators Reptile Park. The town is on Rio Grande, and the Great Lakes Airlines makes three daily flights between Denver and Alamosa.