Explore details about location Colvin Blvd Ext. Colvin Blvd Ext is a location situated within the Tonawanda alongside other areas such as Desmond Drive, Conant Drive, Colvinhurst Drive. Additionally, some smaller parts of Colvin Blvd Ext include specific areas like Willowbend Road, Marlee Drive, Harvington Road adding to the diversity of its landscape.