Be Like Roger: Let’s Theorize

May 28, 2025

A kayaking lichenologist transformed a river trip into a journey of discovery and wonder by asking the group: “Let’s theorize”.

“You noticed all the dead trees on the left side of the river,” Roger said. The syntax created a question, but his tone suggested a statement. I instantly looked to the left bank, eyes wide. I had noticed many things on our first day’s float down the lower Deschutes in Oregon. The dramatic basalt cliffs, the lush sagebrush hillsides, the swirling clouds. I had not noticed anything significant about the left side of the river, and I certainly hadn’t noticed a substantially higher number of dead trees on river left than river right. How could I have missed that?

“Let’s theorize,” Roger said, invitingly.

Roger getting ready to inspire. Photo courtesy of Jasmine.

Roger Rosentreter is a world-famous lichenologist and renowned botanist. He is in his 70s. And he is an incredible kayaker. He styles an old-school Pirouette that might actually be the same age as him. Astonishingly, he has outfitted zero padding into the hard plastic seat of his boat. He worked for the BLM for decades and as a professor. He tells devastating environmental stories, he laughs easily, and his favorite phrase is, without a doubt, “Let’s theorize.” 

Our group took some time to hypothesize in our heads before presenting our partial theory to Professor Rosentreter. “Well,” I started, my heart racing just a little bit. I did not want to answer wrong in front of the class, despite “class” being a riverside chair circle composed of people I know, love, or am related to. “The right side is Bureau of Land Management and National Grassland, and the left side is Reservation… so maybe they are managed differently?” 

“Yeah,” Riely uptook, “Does one side have more cattle activity? That could weaken the riparian zone? Maybe the left bank is less stable because of that?” Roger silently took it in, nodding his head. Casey tossed out something about the flood that happened a few years prior. My dad drew a connection between the two theories. We untangled our ideas and made informed guesses supported by our background knowledge and what we noticed around us. Roger’s astute observation skills brought many data points he had collected to the table.

After a rich discussion, I wanted to know! “Well, what’s the answer?!” I demanded impatiently.

Turns out Roger didn’t know.

This surprised me. Unlike in science class, we weren’t guessing what the teacher already knew: we were figuring it out together. Roger had his own idea, yes, but he didn’t know for sure. He just couldn’t help noticing things. He noticed everything, which made all of us notice more. And it was fun to pay attention to what was around us. We really engaged with the landscape. Then we got to brainstorm in a dialogic space, and we watched Roger’s top hypothesis evolve before our eyes. 

An hour later, while eating strawberry shortcake and discussing something totally different, Roger gasped. Then, led by his fork suspended in midair, he marched through the chair circle. “Look at this syringa!” he demanded excitedly. 

Roger with the author, Jasmine. Photo courtesy of Jasmine.

Using his fork as a pointer, he drew our attention to a growth different from the other branches. “This is evidence for my first hypothesis,” he concluded. It took some explanation for us students to connect the dots, but we finally caught on.

Roger posed a number of questions on that river trip. He taught us a lot about lichen, botany, and environmental management. He demonstrated curiosity and wonder. It was thrilling to wander through the landscape the way Roger does. Every noticing is a thing to wonder about. Every plant has a story to tell about the landscape. And it wasn’t just interesting, it also felt good. Turns out noticing is good for your health. 

It, of course, feels good to be in nature, but to notice nature is one step further. Research shows that when you intentionally notice, it increases your sense of well-being and connectedness. We feel positive emotions like awe and hope. And of course, when we take time to acknowledge those feelings, it strengthens them. Under the tutelage of Roger, we felt a lot of awe. We felt reverence for the landscape. We felt connected to nature. And we were learning a ton.

Anytime we couldn’t find Roger, we could count on him wandering back into camp an hour or two later with a gallon-size Ziplock filled with little white and brown sample envelopes. He’d tell us about the lichens he found and questions they made him ask, inevitably followed by, “Let’s theorize.”

Evening walks were not about the distance covered. Instead, they focused on new knowledge gained and new wonders noticed. Roger is an investigator, and nature is full of evidence. He reminded us that nature holds more than just beautiful cliffs and idyllic skyscapes. Walking through the world like Roger means fostering a greater connection to the land. It means curiosity and inquiry. It means experiencing the power of childlike wonder. It means missing less.

We never decided for sure what was causing the dead trees to be more prominent on the left side of the river. In fact, we had a number of hypotheses still open for debate. It didn’t matter, though. What mattered is that, because of Roger, we started looking for questions and we asked nature for answers. We looked harder, and we listened more deeply. We started to see the land for all it could teach us. And it made everything more vivid. I hope we can all be more like Roger.  Whether on your next river trip or just on a walk in our neighborhoods — pause, notice, and revel in the awe, wonder, and curiosity. It is all around.

From Boise, Idaho, Jasmine Wilhelm has guided on the remote Salmon River system for a decade. She spends her off-season adventuring, freelance writing, and reading voraciously. Follow her writing on Instagram @jasminewilhelm20.8