An American police procedural series, set in an unspecified rural area of the American West. The main character Dan Mathews orchestrates the activities of highway patrolmen against the regional operations of smugglers, hijackers, and robbers. The patrolmen also keep an eye on people who illegally cross the borders between the United States and Mexico. A key element of the show is two-way radio communication among patrol cars and headquarters. Several of the scripts are based on authentic stories from the files of highway patrol headquarters throughout the country.