Of all the magnificent wonders that can be seen in Idaho, our wild and rugged rivers are a particularly treasured. Water forms the heart and soul of Idaho, after all! But did you know that Idaho is also home to a series of lost rivers that – quite literally – disappear? The product of Idaho’s tumultuous and volcanic geology, these these underground rivers actually make quite the journey… and it’s fascinating!

The Lost River Range in Central Idaho is stunning, to say the least. After all, it is where seven of Idaho’s tallest mountains are!

Lost Rivers Chamber of Commerce/Facebook Specifically, there are seven peaks over 12,000 feet–including Idaho’s tallest: Mt. Borah.

You might have even heard of the Big and Little Lost Rivers that run through the Lost River Valley, but do you know how all of these places got their names?

Big Lost Ranch While the Big and Little Lost Rivers are technically two different currents, they both head to the same place. The Big Lost Riiver originates in the Pioneer Mountains in Salmon-Challis National Forest, A dam impounds the river and creates Mackay Reservoir. The Little Lost River, on the other hand, flows southeast between the Lost River Range to the west and the Lemhi Range to the east.

Thousands to millions of years ago, the Lost Rivers rushed through the valley, feeding the landscape into a lushly fertile region.

BLMIdaho

As Idaho’s southern half began to undergo serious volcanic activity, however, the continuous lava flows that formed Craters of the Moon began to slowly push the river south.

Lost Rivers Chamber of Commerce/Facebook As the lava flows ceased, the porous basalt rock bed of what is now known as the Snake River Plain began to absorb the river–well, at least the part that was trying to flow through it. Essentially, the two rivers disappear at this spot.

It’s called the “Sinking Point,” or the “Sinks.”

Lost Rivers Chamber of Commerce

As the water becomes subterranean, it collides with the Snake River Aquifer and continues its journey… underground.

Evan DeHamer/Flickr

But the powerful Lost Rivers aren’t “lost” forever.

Lost River Chamber of Commerce/Facebook

Instead, these ancient waters continue underground for well over 100 miles and pour out of the rocks at Thousand Springs State Park.

Thousand Springs State Park/Facebook

The surprising and beautiful Thousand Springs, Minnie Miller Springs, and other hidden springs around Hagerman are the end-product of this unique journey for Idaho’s river waters.

Charles Knowles/Flickr A visit to this multi-unit park complex offers plenty of opportunities to see the springs themselves as well as other waterfalls, canyon gorges, and historic fossil beds. Definitely a bucket list must-see for any visitor!

Who knew? Even hundreds of feet underground, Idaho is still spectacular!

Lost Rivers Chamber of Commerce/Facebook

Specifically, there are seven peaks over 12,000 feet–including Idaho’s tallest: Mt. Borah.

Big Lost Ranch

While the Big and Little Lost Rivers are technically two different currents, they both head to the same place. The Big Lost Riiver originates in the Pioneer Mountains in Salmon-Challis National Forest, A dam impounds the river and creates Mackay Reservoir. The Little Lost River, on the other hand, flows southeast between the Lost River Range to the west and the Lemhi Range to the east.

BLMIdaho

As the lava flows ceased, the porous basalt rock bed of what is now known as the Snake River Plain began to absorb the river–well, at least the part that was trying to flow through it. Essentially, the two rivers disappear at this spot.

Lost Rivers Chamber of Commerce

Evan DeHamer/Flickr

Lost River Chamber of Commerce/Facebook

Thousand Springs State Park/Facebook

Charles Knowles/Flickr

A visit to this multi-unit park complex offers plenty of opportunities to see the springs themselves as well as other waterfalls, canyon gorges, and historic fossil beds. Definitely a bucket list must-see for any visitor!

If you’ve ever been to Thousand Springs or played around in the Lost River Valley, share your photos with us! What other hidden gems are nearby?

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