As project geologist at Noranda Exploration in Yellowknife, Douglas Bryan influenced the Courageous Lake and Musk base metal deposit discoveries. As district geologist, still with Noranda, he moved to British Columbia and was later transferred to New Brunswick. In 1986, he formed Covello, Bryan and Associates in Yellowknife. He was instrumental in the decision to stake the claims that host the Diavik diamond mine. Bryan went on to become the manager of geology, Diavik Diamond Mines in 1997.

Respected for his expertise, Bryan became vice-president of Allyn Resources before managing exploration programs for Aurora Geosciences Ltd., North Arrow Minerals, Manson Creek Resources and Forsys Minerals, covering the Yukon, Northwest Territories, Nunavut, Saskatchewan, British Columbia and Namibia.

Bryan was past president of the NWT Chamber of Mines. In 2010, he received the NAPEG Award of Merit for his contribution to mineral exploration in the North.