Five years ago, Shannon Donahue read a newspaper story about a biologist who studied interactions between people and bears along the Chilkoot River.

“I didn’t realize before then that there was a whole field of study on human-bear interactions,” Donahue said.

Several years of field work and a master’s degree later, Donahue is the new bear monitor at Chilkoot, charged with keeping the peace between anglers, wildlife viewers, and brown bears in the narrow,…