Exploring Oregon's Caves and Waves

Ride the rapids!" urged our guide, Steve. "Go on, jump out!"

When nobody on our six-person raft leapt at the offer, I decided someone needed to take the plunge. I straightened my life jacket and aimed for the whitest water.

As it turns out, a boatless rapids shoot was the only bad move I made during our family vacation in southern Oregon, which included white-water rafting on the Rogue River, the Oregon National Caves Monument and Crater Lake. On our way south, we included Lassen Volcanic Park in northern California.

In a way, it was too bad we didn't visit the caves first. Their motto is education and restoration (no hot-dogging allowed). Park officials have undertaken an ambitious project to erase the effects of a century of human intrusion.

As we progressed through the most interesting parts of our vacation along what is known as the Pacific Ring of Fire, learning combined with a respect for nature became our approach. But not soon enough for the white water, where not surprisingly, I hit a rock - a big, round one that was the source of a showy plume of wake.

Our guide had instructed me to rappel off the rocks with my feet, which were pointed down river. But this technique assumes visual warning and time to react. Floating through splashy rapids doesn't allow for either. I don't recommend it, especially this summer where rivers are unusually high from the winter rains - and therefore, more treacherous than usual. I was pulled from the river, shaken but intact, with a quiet vow to stick with the educational side of our vacation from then on.

We based ourselves in Ashland, and after reading up on the region's geology, we plotted our course. The Pacific Ring of Fire is a vast circle of volcanoes and earthquakes that mark the edge of plates that form the earth's crust. We decided to go for altitude first - Crater Lake, which is part of the Cascade Range extending from Canada all the way south to Lassen in California.

Crater Lake is nearly 9,000 feet above sea level. It is a pristine 1,932 feet deep expanse of sapphire-blue water dropped like a mirror in the old caldera (a crater formed by an eruption) of a collapsed volcano. It is the deepest lake in the country, the second deepest in the Western Hemisphere and the seventh in the world.

After a two-hour drive, we were rewarded by a summer's day of play in 15 feet of snow at the edge of an eerily calm wonder of the world. It was hard to believe that we were standing where a natural cataclysm had taken place some 7,700 years ago.

Our children were fascinated by the notion that we were standing inside the perimeter of an old volcano. (They glimpsed a little of the sensation at Lassen, when we stood over the bubbling sulphur springs and imagined what it would feel like to experience an actual eruption. Hot, we decided, and smelly, due to the sulphur.)

We took the scenic route home, south through Klamath Falls, home to spectacular bird sanctuaries. We turned west. The route was longer, but the Swiss alp-like countryside and winding, mountain roads made the trip home a destination itself. All the cows had bells, the horses looked wild, and who can quibble with a wonderland that sports signs such as "Warning: peacock crossing"?

Next, we opted for some internal geology. After a 90-minute drive from Ashland, we penetrated the limey-ooze of the marble caves. The children were impressed with the size of the formations, from slimy stalactites to the cave popcorn and flowstone (see box, above).

We snaked through what began to feel like endless tunnels with low overheads (they charge for the hard hats, but they're worth it - nearly everyone on the tour beaned themselves more than once). But we were soon diverted by our abrupt emergence into the Ghost Room, a cavernous display of the region's typical cave formations.

It was hard to imagine the sensation of the first explorer, a man named Elijah Davidson who wandered unsuspecting into this alien terrain in pursuit of his dog, who happened to sniff a bear in the dark.

After a dim, circuitous journey through areas with names such as River Styx and Petrified Gardens, the afternoon light was a welcome sight.

Our last stop, Lassen Volcanic National Park, was the perfect experiential counterpoint to the high mountain lake and craggy earthen bowels of the caves. It was alive and smoking, but in the clear air, so the threat seemed less ominous. After we viewed the visitor-center videos and saw footage of a 1914 eruption, however, we were less cool. We took the "Boiling water: beware!" signs seriously and stayed firmly on the footpaths through the bubbly oozes.

We collapsed into the car for a drive south to L.A., but we were treated to a final reminder of the region's picturesque geology: Snow-peaked Mt. Shasta reigned on our horizon for nearly three hours as we finished our adventure.

A look at common formations found in caves:

* Calcite - A crystalline form of calcium carbonate, the chief mineral in limestone, chalk, cave formations, and marble.

* Flowstone - Calcite deposited by water running down a cave wall or over a cave floor.

* Popcorn - Calcite formations that look like little pieces of the popular movie snack.

* Speleothem - A general term used to describe deposits in caves.

* Stalactite - A calcium carbonate speleothem which grows downward, like an icicle, as a result of deposits left by dripping water.

* Stalagmite - A deposit of calcium carbonate built upward from a cave by dripping water.