Co-written by an anthropologist and a reindeer herder (BRISK project co-researcher) on the basis of their field materials, this book offers documentation and analysis of complex traditional environmental knowledge. After discussing the methodology of the Evenki community-based transdisciplinary observatory for monitoring climate and environmental changes with herders (2012–2016), the book reveals some of the results of this co-production. It presents the emic typologies and concepts the Evenki use for understanding norms and anomalies, observing and predicting changes, and adaptating. Conceived together with the herders, the book’s structure combines analytical texts (traditional in anthropology) and other forms of presentation, such as abstract diagrams with explanations in Evenki, Russian, and English, diagrams on pictures, and encyclopaedic entries with pictures and trilingual explanations from the herders.