A typical prairie slough in the Sheyenne River drainage. Cookie, a German wirehaired pointer, is looking for sharp-tailed grouse.

I left my hosts’ home in North Dakota on Wednesday for the two-day drive home. On I-94 east of Jamestown, N.D., I saw a sign proclaiming the Continental Divide, elevation 1,400-something feet.

“What the hell?” I thought, being a good Coloradan. “What is the Continental Divide doing here? And so low!”

Then it hit me: I had spent the previous few days along and near the Sheyenne River, which flows into the Red River of the North, which flows into Lake Winnipeg, which in turn discharges into Hudson Bay.

In other words, I had just crossed from the Arctic Ocean drainage back into the Atlantic Ocean’s. Almost immediately the land became drier, with fewer sloughs, and I started spotting a few center-pivot sprinklers. Yikes, the Arctic! And without even entering Canada.

Autumn, however, has progressed farther here in southern Colorado: willows and Gambel oaks are turning color.