Arizona Public Service completed a 110-mile power line connecting Phoenix to Yuma. The line is one of the largest transmission construction projects in the West.

The power line will improve the reliability of service to people living in the Yuma area.

Planning for the line began more than a decade ago due in large part to an increase in the area’s population. Construction began in 2013 and cost $200 million.

According to APS, what made the project especially challenging was that the line was constructed in some of the most isolated and rugged parts of the state.