Trashigang Dzongkhag shares its border with Indian state of Arunachal Pradesh in the east. It is 551 kms away from Thimphu and is one of the largest Dzongkhags in the Kingdom. The altitude elevation ranges from 600 m to over 4500 m above sea level. The climate is mainly temperate with an annual rainfall between 1000 mm and 2000 mm.
This Dzongkhag has a total area of 2204.5 square kilometers. It has a total of 8,610 households with population of over 71,768. The density of population is 33 per sq.km. The forest cover accounts for 77.87 percent of the total and the Dzongkhag has arable land of 3.64 percent of its total area.
The Dzongkhag Administration Headquarters and the main town are located at Mithidrang, which falls under Samkhar Gewog. The Dzong is used as the Dzongkhag Headquarters and also as the seat of Dzongkhag Rabdhey.
Trashigang Dzongkhag is administratively divided into three Dungkhags, 15 Gewogs and 79 Chiwogs including a Thromde. All the gewogs, except Sakteng are connected with motorable roads.