Oppdal is a municipality in the county of Sør-Trøndelag, Norway. Oppdal is bordered by one municipality in Sør-Trøndelag (Rennebu to the northeast), three municipalities in Møre og Romsdal county (Surnadal on the north as well as Rindal and Sunndal to the west), two municipalities in Hedmark county (Tynset on the east and Folldal on the south), and one municipality in Oppland county (Dovre to the south). The municipality covers an area equal to the entire county of Vestfold. The administrative centre is at 545 meters above sea level, and is said to have the best public drinking water in Norway. Most of Oppdal's area is mountainous, much of it above the treeline. In the valleys around creeks and the river, there are some spruce and pine woods; closer to the treeline, birches dominate. There are several lakes in the municipality, the most famous being Gjevilvatnet, a particularly scenic lake with hiking and cross-country skiing trails around.