As I couldn't get a good view of the Mount Rushmore yesterday, I tried again this morning. The four faces were clearly viewed in the morning sun. There seemed to have an commencement. I saw many young guys in cap and gown. I asked a woman in a visitor center and knew that they were students of Hill City College or University. It's really wonderful to have a commencement at this kind of place. I wanted to see the ceremony but I couldn't take time.

I went down the hill to the I-90. There was nothing but green hills along the I-90. It sounds like a view of ranches in Colorado, but it was different in the sense that there were more up and downs here. I enjoyed beautiful green landscape, thinking that it should be completely different in winter. After 1 hour, I crossed the state line of Wyoming, although nothing changed in landscape. I switched to the US-14 and reached the Devil's Tower via the state-24. The shape of the tower was unique enough to make me curious about its forming process. I read a brochure to know that the tower is solidified magma of volcano about 60 million years ago. And the column was exposed by a long time erosion. So, we can say that it's just like a pimple of the earth. There were 1.3 mile trail around the tower but I didn't go around. I ate a Subway sub and left the tower.

I went back to the I-90 west. It seemed that the highest density of population was on highway, although I could see 1 car every about 10 minutes. Two and half hours later, I crossed the state line of Montana. I could have reached the Yellowstone National Park without entering Montana, but I kept on the I-90. That's because I wanted to see "the large sky" of Montana. Unfortunately, I had dark clouds and occasional showers this evening. At the state line, I stopped to figure out how close to the Yellowstone National Park I could go. I decided to reach Billings, about 100 miles away from the line. I drove for 1 and half more hours and stopped at 19:30. In spite of the memorial holiday weekend, I was lucky enough to get the last room in the motel 6.