Lunch and Snack examine a reconstructed covered wagon on the actual path of the Oregon Trail where it crosses Whitman Mission National Historic Site southwest of Walla Walla. The mission, a rest stop along the trail, was the site of the 1847 massacre that played a key role in America's westward expansion.

After the massacre, where members of the Cayuse Tribe killed the Whitman family, who operated the mission, their adopted children and other people present at the complex, the dead were buried in a communal cemetary nearby and a memorial spire was erected on a hill above the site.

Moving on to the Tri-Cities area of southern Washington, Lunch and Snack visit Sacajawea State Park in Pasco. The park, sitting at the confluence of the Snake and the Columbia rivers, was the location of the first encampment of the Lewis and Clark expedition on the Columbia. The state historical society built a stone monument to recognize the accomplishment.

"Gosh Snack, is that what Sacajawea looked like?"

"Nobody really knows. No one can even agree upon how to spell her name. It's often spelled 'Sacagawea'."

A small statue of what historians thought Sacajawea looked like stands in the park's interpretive center. She was the 17-year-old Shoshone guide and interpreter who helped to safely lead Lewis and Clark through Indian territory, making her a key member of the expedition.

Paying homage to the region's prolific wine production, the cows climb up a sculpture of a grape bunch near historic downtown Kennewick.

Before settling in for the night in Kennewick, the intrepid bovines pay a visit to Columbia Park along the banks of the Columbia River where they met a flock of geese and other waterfowl.

"They look hungry."

As the sun set over the Columbia, it was time to plan for the next day's trek down the mighty river.

"Holy windmills Lunch! Those things are EVERYWHERE!"

The bovines stop to admire a group of wind turbines on a hill above the Columbia. Hundreds of turbines dot the landscape of southern Washington and northern Oregon, adding to the power generating capability of the region.

For the second dam of the day, Lunch and Snack take a look at the spillway of the John Day Lock and Dam near Rufus, Ore. The complex didn't allow tours, so the cows had to be content with admiring it from a distance.

"What in the world? This looks vaguely familiar."

The bovines stop at the Maryhill Stonehenge near Maryhill, Wash. Completed in 1929 as a World War I memorial, the structure was built as a replica of what Stonehenge in England might have looked like.

It was familiar because Lunch and Snack had visited the REAL Stonehenge years before.

The Maryhill Stonehenge, made of concrete instead of real stone, attracts thousands of visitors at its perch above the Columbia River.

"You mean it's closed?"

The cows attempted to visit the Goldendale Observatory near Goldendale, but found that no one was there to show them around. The observatory operates as part of the Washington State Park system, but this site was inexplicably closed to much bovine chagrin. The cows were hoping to see one of the observatory's afternoon solar viewing shows.

After regrouping in The Dalles, the dam tour continued with a visit to The Dalles Lock and Dam. This complex provided free tours of the powerhouse and fish ladders. The view of Mount Hood in the distance added to the anticipation.

"Wow! This is amazing."

Even though only two of 22 turbines were operating that day, it was still possible to feel the power in the air.

"Well this was the best one yet, Snack."

The cows took time to plan the next stop on the tour.

Lunch and Snack venture downriver to the Bonneville Lock and Dam near Cascade Locks, Ore. Built with the dual purpose of hydro power and river navigation, the dam also provided a spectacular view of salmon navigating the fish ladder next to the complex's visitor center.

The original powerhouse of the Bonneville Lock and Dam was designated a National Historic Landmark District in 1987.

On the day of the visit, none of the turbines in the powerhouse were generating power, but the Corps of Engineers ranger conducting the tour said a second powerhouse, built on Washington side of the river years later, had working turbines that day. Turbines were often shut down during times of salmon migration to protect the fish, he explained.

With the most of the turbines shut down for fish migration, the water had to go somewhere, so over the spillway it went, producing a rainbow in the rising mist of the flowing river.

Before leaving the Columbia River Valley behind, Lunch and Snack make a stop at Multnomah Falls, one of Oregon's most iconic landmarks near Troutdale. Formed as a result of cataclysmic ice age floods, the falls drop 620 feet over two steps.

Billed as the second tallest waterfall in the U.S., 2 million people a year are drawn to the site with many venturing to the Benson Footbridge for a close-up view.

Heading back north, Lunch and Snack make a jaunt into the Cascades to see Mount St. Helens National Volcanic Monument.

From the Johnston Ridge Visitor Center, the view of the volcano was amazing, but wind sent plumes of ash swirling around the crater and across the lahar that flowed from the mountain during the explosive eruption and landslide of May 18, 1980.

"Whoa Snack. These were huge trees."

Although life has been slowly returning to the area ravaged by the eruption of Mount St. Helens, stumps from blown-down trees are still visible from one of the trails leading from the visitor center, a testament to the power of the volcano.

Lunch and Snack examine a direction pointer placed on Johnston Ridge. From there, they were able to pick out nearby landmarks.

With their journey almost at an end, the cows stop in at Fish Brewing in Olympia for a celebratory sampling of beer.

"You know Lunch, this is a nice way to wrap up another adventure. Cheers!"