Coulee-ites will be treated to a guest lecture from Nick Zentner, a geologist and host of "Nick on the Rocks," which has aired on Pacific Northwest Public Broadcast System stations and is available to watch on YouTube.

Zentner will be at the Grand Coulee Dam Visitor Center March 9, at 1 p.m., to discuss geology in a free lecture sponsored by the Grand Coulee Dam Rotary Club to celebrate their 70th year.

"Grand Coulee is famous for geologists," Zentner said in an email to The Star. "Huge valley carved by the Missoula Floods. We know when and why the coulee was carved. But we're still looking for clues as to how many floods there were. There are also amazing, huge, giant lava flows that buried much of eastern Washington. I'll be talking mostly about new stuff that geologists have found along these two lines."

"The lava flows are 16 million years old," Zentner continued. "The granite is much older. When the Canada Ice Sheet was in your area, the Columbia River was diverted through Grand Coulee and over Dry Falls ... but the sexy story involved the huge floods."

Asked why the coulee area was so different from the neighboring forest and mountains on the Colville Indian Reservation, Zentner explained that "the main reason lies with the great lavas stopping in your area, and not burying the rest of the mountains. Beneath the lavas, there are old mountains."

Unable to find a major in college at first, Zentner dropped out of the University of Wisconsin in the 1980s and began working in Glacier National Park in Montana, where his roommate was a geology major.

"He introduced me to cool geology on hikes in the mountains," Zentner said, adding that he then went back to school in Wisconsin and signed up for Geology 101, which led him down his career path.

First teaching at Miami University in Oxford, Ohio, Zentner and his wife missed the West, and landed in Ellensburg, where he has taught geology at Central Washington University since 1992.

"About 10 years ago, in addition to teaching, I started doing free lectures and field trips for the public," Zentner said. "Word of mouth was strong ... and more and more folks showed up."

In a screenshot from YouTube, Nick Zentner talks about Dry Falls in an episode of TV's "Nick on the Rocks."

Zentner said the CWU president and chief of staff noticed, and they wanted to increase CWU visibility for recruiting students on the west side of the state, so they funded the show "Nick on the Rocks," Zentner's main TV show. "I still record my new lectures for YouTube, and there are followers around the globe," Zentner said. "Amazing."

Zentner received the James Shea Award in 2015, a national award recognizing the exceptional delivery of earth science to the general public.

Zentner said the show has aired on all the PBS stations in Washington, Oregon, and Idaho.

The show focuses on a variety of geology topics: the formations of basalt columns, identifying old river routes through rocks, and more.

One episode, linked in the online edition of this article, features a simulation of what the floods looked like at Dry Falls.