ボンネビル郡の天然記念物・トップ5

Just next to the historic marker you can explore an ancient lava tube: the 17 Mile Cave. The marker gives interesting information about hunters in the area that hunted camels, elephants and giant bisons about 12,000 years ago.

The Hells Half Acre Wilderness Study Area spans over 66,000 acres and is managed by the Bureau of Land Management (BLM). The lava field that covers the area is 5,200 years old. It is a great place to hike and you will most likely be on your own – much different from the crowds in nearby Craters of the Moon National Monument. There is a 2-mile loop trail, the Lava Loop, and you can also venture into the backcountry via the Twentymile Lava Trail to some interesting lava vents. There is not much of a trail though. You are mostly hiking over petrified lava rock and you have to navigate by looking for the next wooden pole. A great little adventure!

Like so many caves around it, the The 17 Mile Cave is a lava tube and a relic from Idahoe's volcanic past (although the area is still very active). They are formed when eruptions cause a lava crust to form, cool down and allow lava to flow through again. Its name comes from the proximity to the town of Idaho Falls. The tube is around a quarter mile long. The entrance is located directly on the West Arco Highway and is accessible to everyone. This is probably one of the reasons why this fantastic natural monument has fallen victim to modern cave "paintings". If you're ever in the area, make sure you bring several light sources and a jacket. It's really cool in there.

Along the Lava Loop you will explore different shapes of lava rock. At this location, the lava cracked open, leaving gaps big and small in the rugged surface.

A large river with a modified urban waterfall, surrounded by different species of plants composing the landscape near the river and the trail. This is one of the most tourist spots in Idaho Falls, with lots of restaurants around, nice gardens along the trail, and a public library close by. Behind the waterfall there’s also a dam, composing a beautiful and relaxing area to visit.

The remote trailhead has a nice picnic area with benches, a bbq and a roof for some shade. You can take a hike into the vast lava landscape by following either the blue loop which is about 1.2 miles long (follow the blue poles) or by following the red poles for the twenty-mile trail that takes you to some spectacular vents. There is even a trail register at the trailhead.