He is known for his fieldwork among many different Amerindian cultures such as in the Amazonian tropical rainforests (e.g. Desana Tucano), and also among dozens of other indigenous groups in Colombia in the Caribbean Coast (such as the Kogi of the Sierra Nevada de Santa Marta), as well as others living in the Pacific Coast, Llanos Orientales, and in the Andean and inter-Andean regions (Muisca) as well as in other areas of Colombia, and he also did research on campesino societies.

For nearly six decades he advanced ethnographic and anthropological studies, as well as archeological research, and as a scholar was a prolific writer and public figure renowned as a staunch defender of indigenous peoples.

Reichel-Dolmatoff has worked with other archaeologists and anthropologists such as Marianne Cardale de Schrimpff, Ana María Groot, Gonzalo Correal Urrego and others.

[2] Reichel-Dolmatoff spent the rest of his life in research in the fields of anthropology, archaeology, ethnoecology, ethnohistory, ethnoastronomy, material culture, art, and vernacular architecture, among others.

[citation needed] In a trip to the upper Meta River in the Orinoco plains in 1940, he conducted research and later published the earliest studies done on the Guahibo Indians.

For the next five years, Gerardo and his colleague and wife conducted research throughout the Sierra Nevada de Santa Marta region, focusing particularly on the Tairona descendants, the Kogui, also known as the Kogi or Kaggaba, and also worked with the Arhuaco and Wiwa indigenous groups, as well as ethnography of a peasant community among the people of Aritama (Kankuamo).

Reichel-Dolmatoff was the single author of 40 books and of over 400 articles, all dedicated to the archeology and anthropology of Colombia and specifically highlighting the relevance of indigenous peoples of the past and present.

Reichel-Dolmatoff researched origins of early chiefdoms and explained the millenarian evolution of Amerindian cultures and their links to contemporary indigenous groups.

At a conference in 1987, Reichel-Dolmatoff spoke the following words: "Today I must acknowledge that since the beginning of the 1940s, it has been for me a real privilege to live with, and also try to understand in depth, diverse indigenous groups.

What I did find was a world with a philosophy so coherent, with morals so high, with social and political organizations of great complexity, and with sound environmental management based on well-founded knowledge.

All of this more and more made my admiration grow for the dignity, the intelligence and the wisdom of these aborigines, who not least have developed wondrous dynamics and forms of resistance thanks to which so-called ‘civilization’ has not been able to exterminate them.

Maybe I am too optimistic, but I think that anthropologists of the older and new generations, according to their epochs and the changing roles of the Social Sciences, have contributed to revealing new dimensions of the Colombian people and of nationhood.

I also have trust that our anthropological work constitutes an input to the indigenous communities themselves, and to their persistent effort to attain the respect, in the largest sense of the term, that is owed to them within Colombian society.

I do not think that it is possible to advance towards the future without building upon the knowledge of the proper millenarian history, nor overlook what occurred to the indigenous peoples nor the black populations (Afrodescendants) during the Conquest and the Colonies, and also during the Republic and to this day.