BEND, Ore. — It’s probably a good thing no one pointed out, until the end of my trip, that I was doing a “volcano tour” of Central Oregon on the anniversary of the Mount St. Helens eruption. Earth-moving forces are apparent enough in this part of the world without a reminder of what can happen when those pointy peaks lose their patience.

As it was, I had no trouble imagining the eruptions that formed this landscape thousands of years ago.

Hundreds of cinder cones dot this high desert, some of them black and crumbly, others tan and tree-covered. The snow-covered peaks of Three Sisters and Mount Bachelor rise to the west.

The biggest draw for me on this trip was Newberry National Volcanic Monument, a sprawling paradise for recreationists of all sorts as well as volcano nerds.

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Newberry Caldera is the monument’s centerpiece. Its topless-cone shape — somewhat similar to Crater Lake, with Paulina (pronounced with a long “i” sound) Peak as its highest edge — tells its story. This 500-square-mile volcano shield has seen a lot of activity over the millennia, and surrounding cones and crags are results of fissures, eruptions and flows.

I explored the area in mid-May not because of the date’s volcanic significance but because that is when most of the monument’s roads are snow-free. It’s also when lava tubes are bat-free — it’s not that bats are dangerous to humans; just the opposite — and open to visitors.

Tube time

A lava tube is a type of cave formed when red-hot volcanic lava flows like a river. The river’s outer walls solidify first, allowing molten rock to flow inside them until the eruption ends. When the last of the lava flows out, it leaves a hollow tube, parts of which open to the surface when ceiling sections collapse. (Ape Cave, near Mount St. Helens, is the longest lava tube in the United States.)

These tubes might not sound like a safe place for exploration. But as my Wanderlust Tours guide, Jeff Gartzke, explained as we wandered through one, they are actually very stable once they’ve completely solidified.

The area around Newberry contains a number of lava caves, most them rarely visited. Wanderlust has permits to take people into a handful of caves that are not open to the public. This one felt spacious, with 15-foot ceilings and great acoustics in many places.

The most accessible lava tube in the monument is Lava River Cave, just off Highway 97 near the Lava Lands Visitor Center. Like most caves, lava tubes are completely dark and maintain a constant temperature in the 40s, so bring a jacket and at least two light sources or rent a lantern at the cave entrance.

Unlike many caves open to the public, these have not been modified much, which can mean loose footing when you come upon fallen rock inside.

Lava tubes tend to be rounded in shape, with inner surfaces pockmarked by bursting volcanic-gas bubbles and “lavacicles” formed when still-liquid lava dripped. In some places, cracks allow you to see layers of cave wall laid down by successive eruptions.

Up top

The monument has plenty to offer for those who prefer to remain above ground, and seeing the highlights takes at least a couple days. It’s easy to stick around: A vast number of well-appointed campgrounds populate the monument and surrounding state parks.

Stop in at the Lava Lands Visitor Center in the north section and drive to the top of the Lava Butte Cinder Cone. Panels inside the fire lookout on its edge tell you the names of surrounding peaks and cones. Stretch your legs (and warm up if you’ve been in Lava River Cave) on a short hike to nearby Benham Falls.

Head south and east for 25 miles to investigate Newberry Caldera and the Paulina Visitor Center. A short and potentially sharp hike leads onto the Big Obsidian Field, a volcanic flow a mere 1,300 years old. (Did I mention that Newberry, like Mount Bachelor and the South Sister, is not extinct?) The obsidian — essentially black glass — sparkles on sunny days.

The “Paulina plunge,” popular with locals, entails cycling up and down the road leading to the top of the caldera and then taking a dip in a waterfall pool.

Two lakes containing trout and salmon are nestled atop the Newberry Caldera. Both lakes have convenience stores, rustic lodges and cabins as well as campground spots for rent. For the best panorama of everything the monument encompasses, drive or hike all the way to the top of 7,894-foot Paulina Peak.

And if you find yourself getting worried about volcanic activity, consider indulging in another thing central Oregon is famous for: beer.

Christy Karras is a Seattle-based freelance writer.