While we slept, the ship passed through two locks to deliver us to the confluence of the Palouse River and the mighty Snake River where a cloud-filled sky greeted early guests on the bow to watch the black of night slowly fade to gray. The clacking of a seemingly never-ending coal train traversing a high steel trestle bridge overhead matched the rhythm of a guest spinning a stationary bike on the aft sun deck.

Dampened by the heavy cloud cover, the sun’s warmth was slow to arrive in the high desert and we enjoyed a cool morning of marveling at the dozens of visible layers of volcanic rock. Interlocked hexagonal columns of basalt rising from the impounded waters of the once-wild Snake River. Ancient slide rock tumbled below the cliffs, creating a pebbled skirt hiding the geologic unknown beneath.

As the morning aged, winds developed to whitecap the waters, scatter the clouds, and deliver a gentle warming for our outings. A short Zodiac ride delivered us to waiting buses that climbed out of the valley to a sage-covered landscape crisscrossed with mule deer trails and watched over by the keen eyes of raptors&mdashlow-flying harriers looking to ambush unsuspecting rodents, kestrels seeking songbirds and large insects, high-soaring red-tail hawk spying

Our ride deposited us above the face of a nearly 300-foot waterfall thundering through a canyon washed out of the plain more than 10,000 years ago by earth-sculpting glacial floods the scale of which we could hardly imagine, reminding us how glaciers shaped massive swaths of land that were never even covered by the mile-thick ice.

Following our visit with the waterfall, we cruised by Zodiac for close-up looks at the basalt cliffs where the barnacle-shaped mud nests of cliff swallows clung to the rock, and cattails willowed in the wind at the edge of massive flood deposits.

Leaving the Palouse, curious souls boarded the Zodiacs and entered the Lower Monumental Dam lock alongside the National Geographic Sea Lion for the 100-foot drop on our slow, stepped descent to the Columbia River. On the other side of the dam, a pair of white pelicans reminded us of how connected the desert is to the sea. They piqued our curiosity about what other wonders await ahead.