Argentine Pass facts for kids

Argentine Pass is a very high mountain pass in the Front Range of the Rocky Mountains in central Colorado, United States. It sits at an elevation of 13,207 ft (4,025 m). This pass crosses the Continental Divide, which is like a giant imaginary line across North America. Rivers on one side flow to the Atlantic Ocean, and rivers on the other side flow to the Pacific Ocean.

Argentine Pass is located on the top of the Front Range mountains. It forms the border between Clear Creek and Summit counties. It's southwest of Georgetown and is known as the highest pass in Colorado that vehicles can reach, even if the road isn't paved.

Long ago, this pass had other names. In 1867, people called it Sanderson Pass. A map from 1869 showed it as the Snake River Pass.

What is Argentine Pass Like?

Argentine Pass is about 0.94 miles (1.51 km) north of Argentine Peak. It's also about 0.95 miles (1.53 km) southwest of Mount Edwards.

On the east side of the pass, you'll find the valley of Leavenworth Creek. This creek flows into South Clear Creek near Georgetown. To the west, there's a deep, bowl-shaped valley called Horseshoe Basin. This basin is where Peru Creek starts, which then flows into the Snake River near Montezuma.

The Continental Divide at Argentine Pass also marks the boundary between Clear Creek and Summit counties.

In the past, a toll road and stagecoach route used this pass. The path on the west side is what's left of that old road. On the east side, the Argentine Central Railway ran from Georgetown to the pass. This railway operated from 1906 to 1918. Today, a Jeep trail to the pass follows the path of this old railroad.

A Look Back: History of the Pass

Silver Discovery and Mining

On September 14, 1864, an important discovery happened near Argentine Pass. A former governor named Robert Steele, along with James Huff and Robert Layton, found silver high on McClellan Mountain. This mountain is about 1.85 miles (2.98 km) north of the pass.

The rocks in this area mostly contain granite and gneiss. But they also have veins with silver-rich minerals like galena and blende (which is sphalerite). Other minerals found include iron pyrite and chalcopyrite. This was the first big discovery of silver ore in Colorado.

They named their discovery the Belmont Lode, which means "beautiful mountain" in French. The area around it became known as the Argentine mining district. "Argentine" comes from argentum, the Latin word for silver.

This discovery helped Georgetown grow into a major center for silver mining. However, mining was difficult due to not knowing how to process the ore well. Also, transporting the ore was expensive, and the high-altitude climate was harsh. Eventually, both sides of the pass were heavily mined. The area was split into East Argentine and West Argentine Districts, with the pass dividing them. You can still see many signs of old mining activity there today.

Old Roads and Railways

Work on a toll road over Argentine Pass started in 1869. It usually cost one dollar for a team of horses and a wagon to cross. In 1883, the counties bought the road to make it a public highway. That same year, the Denver, South Park and Pacific Railroad reached Dillon. This meant most freight traffic no longer used the toll road.

By 1885, a stagecoach ride from Georgetown to Chihuahua, about 15 miles (24 km) away over the pass, cost $2.50. The counties didn't maintain the road very well, and it slowly became too rough for wagons. A town called Waldorf was built on the east side of the pass as a rest stop.

In 1875, the Hayden Survey reported that the Argentine Pass wagon road was the highest wagon road in Colorado. At that time, it was the main route from Georgetown to mining towns like Breckenridge and Montezuma.

Telephone Lines and Power

In 1899, Colorado Telephone laid the first telephone line across Argentine Pass. This was a simple twisted-pair line placed directly on the ground. But it was replaced a year later with a stronger cable. This cable carried 6 toll lines and needed a lot of repairs. It was replaced completely three times before they stopped using it in 1909. Small animals called conies (pikas) chewed on the line, causing major damage. Rock slides also broke the line.

From 1909 to 1916, twisted-pair lines were used again, and they had to be replaced every year. Finally, in 1916, Mountain States Telephone & Telegraph Company built a very strong overhead line. They brought supplies by train to Waldorf and then by pack train up the mountain. This line was only 1.3 miles (2.1 km) long. But it cost over 7 times more than a similar line in easier areas. It was worth the cost because it was the only telephone connection from Denver to Leadville and the western part of Colorado.

Around 1909, the Central Colorado Power Co. started sending electricity over the Shoshone Transmission Line. This line brought power from Glenwood Springs to Denver. This three-phase 90 kV line split into two parallel lines for about 3-mile (4.8 km) as it crossed Argentine Pass. Today, this power line crosses the Continental Divide about 1.25 miles (2.01 km) south of Argentine Pass.

The Vidler Tunnel

The Vidler Tunnel under Argentine Pass started as a silver mine called the Horseshoe tunnel. In 1902, Reese Vidler bought the mine. He planned to extend it under the Continental Divide to make a railroad tunnel. Work continued for a while, but it stopped in 1911.

In 1952, Herbert T. Young bought the unfinished tunnel. He also bought water rights on the west side of the divide. He wanted to finish the tunnel to move water. The 1.4-mile (2.3 km) tunnel was completed in late 1968. Today, the City of Golden owns it. In 2007, major repairs were done to the tunnel's east entrance. This project helps move water and can carry about 31.5 cubic feet per second (0.89 m³/s) of water. On average, it moves about 650 acre-feet (802,000 m³) of water each year.

Weather at the Pass

The weather at Argentine Pass can be very extreme. In 1912, the highest wind speed recorded was 165 miles per hour (266 km/h). At that point, the wind was so strong it blew away the measuring equipment! Temperatures as low as −59 °F (−50.6 °C) have been recorded. Snow drifts can be as deep as 30 feet (9.1 m) and sometimes last until August. This weather information was likely collected by the people building the Shoshone Transmission Line.

Traveling the Pass Today

Today, you can only drive on the Georgetown side of the pass during the summer months. You need a four-wheel drive vehicle that sits high off the ground. The trail on the Horseshoe Basin side is only for people walking or riding mountain bikes. Argentine Pass is the highest point on the American Discovery Trail, a long trail that crosses the United States.