Telegraph Pass (Arizona) facts for kids

Telegraph Pass is a special section of Interstate 8 highway. It goes through the Gila Mountains in southwestern Arizona. This pass is about 19 miles (30 km) east of Yuma. It is located in the northwest part of the Sonoran Desert. The highway here was opened in 1967.

What's in a Name?

Telegraph Pass got its name from an old telegraph line. This line connected San Diego, California to Maricopa Wells, Arizona. In 1873, the US Army extended this line to Prescott, Arizona. There is also a popular walking path nearby called the Telegraph Pass Trailhead.

Exploring the Geography

Telegraph Pass is home to some of the oldest geological features along the Interstate Highway System. The highway cuts through the Gila Mountains. You can see different layers of rock here. These rock layers are some of the oldest metamorphic rocks in Arizona. They are almost as old as the rocks at the bottom of the Grand Canyon.

The main rock found here is called gneiss. It is about 1.6 to 1.8 billion years old. The Gila Mountains themselves formed more recently. This happened over the last 30 million years. It was due to the Earth's crust stretching in an area called the Basin and Range Province.

The tallest point in the dry Gila Mountains is Sheep Peak. It stands at 3,156 feet (962 meters) high.