The Uragas were a tribe mentioned in Mahabharata several times. Their territory named Uraga was also mentioned once. Arjuna during his military campaign to the north and north-western territories had visited Uraga. It was then ruled by a king named Rochamana. From all the references (more than 40) in Mahabharata it is understood that this tribe were a snake worshiping people. Hence they were often mentioned as one of the several Naga tribes, the snake worshiping people of ancient India, who often were themselves depicted as snakes. They were often mentioned along with other related tribes like the the Suparnas, the Rakshasas, the Pisachas, the Yakshas, the Kinnaras, the Kimpurushas, the Gandharvas and the Danavas. They were mentioned as possessed of wisdom and intelligence acquainted with the history of the Kuru race (the race of the Pandava Arjuna). Uragas were often mentioned as great and mighty.
Arjuna's visit to Uraga
We have the following passage in Mahabharata at Mbh.2.26:-
Having vanquished in battle the Puru king, as also the robber tribes, of the mountains, the son of Pandu (Arjuna) brought under his sway the seven tribes called Utsava-sanketa. That bull of the Kshatriya race then defeated the brave Kshatriyas of Kashmira and also king Lohita along with ten minor chiefs. Then the Trigartas, the Daravas, the Kokonadas, and various other Kshatriyas, O king, advanced against the son of Pandu. That Prince of the Kuru race then took the delightful town of Avisari, and then brought under his sway Rochamana ruling in Uraga. Then the son of Indra viz. Arjuna, putting forth his might, pressed the delightful town of Singhapura that was well-protected with various weapons.
Arjuna started his journey from his city Indraprastha (Indraprast in Delhi) and traveled to the north and north-west. Utsava Sanketas were seven hilly Kinnara tribes whose territories were identified to be around Rampur-Bushar, in Shimla district of Himachal_Pradesh. Kashmira mentioned here is the Kashmir valley and Lohita is Leh. Trigarta mentioned here is identified to be Jalandhar in Punjab. The town Avisari belonged to the tribe named Abhisaras, whose territories were part of the Kamboja territories. Abhisara was situated in the Poonch, Rajauri and Nowshera districts of Jammu and Kashmir. Simhapura (Singur town; 35° 53' 47N, 71° 47' 45E; in Chitral district of North-West_Frontier_Province of Pakistan) was a city of the Kambojas whose territories lied in and around Kashmir.
Thus the geography is clearly within the regions in around Kashmir. The location of the Uraga mentioned in this passage of Mahabharata is identified to be Hazara region of Pakistan to the west of Kashmir. It was also known by the name Urasa. The town named Uri in Kashmir seems to be a city of Uragas.
Other Uraga territories
Mahabharata mentions about other Uraga territories around Kailasa (Kailas). Brothers of Arjuna including Yudhisthira visited this place during their trek in high Himalaya mountains.(Mbh.3.158. Another interesting mention is where Arjuna is told to acquire weapons from the Uragas, along with thosehe from other tribes after reaching Indra's abode, ie the territories of Devas believed to be lying towards the east of Kailasa.
Migration of Uragas
Uragas like other Naga tribes has spread through out the world. They are known with different names like Urak, Uruk, Urag, Urug, Urakh, Urukh, Uraca, Urasa etc. Their original homeland seems to be in Ethiopia where they were known by the names like Uracce, Urakur, Urabe and Urabas. From there they migrated to Urak in Baluchistan and to the Uraga territories around Kashmir mentioned in Mahabharata. From Urak, they went to Uruk in Iraq establishing a great civilization there. The Uragas around Kashmir later migrated to Central Asia (Urakh, Urakain), Russia (Urakov), Mongolia (Urag), China (Uruk), Korea (Uraegi) and Japan (Uraga). Another branch migrated to South East Asia (Uruk, Urak) and Australia (Uragara). From Iraq (Uruk) and Russia (Urakov) they migrated to Europe (Uruga, Urug, Urak, Urake, Urasa) and finally reached South America (Uraca, Uraco, Urabo, Uraba, Uruguay).