Garhwal is smack in the middle of the Himalayas, with Himachal Pradesh in the West and North-West; Tibet in the North; the plains of Western Uttar Pradesh in the South and Kumaon in the East.
Historically, it has been described in the ancient text of Kedarkhand to extend from Gangadwar (modern day Hardwar) in the South to the high mountains in the North, and from the Tamsa (Tons) river in the in the West to Buddhachal (probably the Nanda Devi group of peaks between Garhwal and Kumaon) in the East. 
Today it is an administrative division of the raising state of Uttaranchal, comprising the districts of Chamoli, Dehradun, Pauri, Tehri and Uttarkashi. 
The history of Garhwal is older than that of the Ramayan and Maha- bharata.It is a land of popular myths, like that of Lord Shiva appearing as Kirat, 

of Urvashi, Shakuntala and the Kauravas and Pandavas. Worship of Lord Shiva is pre-dominant in this region.  In earliest times, Garhwal was known as Kedarkhand, or the region of Kedarnath. Scriptural texts mention a number of tribes that inhabited the region, such as the Sakas, the Nagas, Khasas, Hunas and Kiratas. The Nagas were a mysterious race whose traces are still to be found in the Hills. The hooded snake was sacred to them, hence their name. (Naga-Snake)
The Khasas were the dominant race in the Garhwal and Kumaon Himalayas till the coming of the Rajputs and Brahmins from the plains. 
According to one version, Garhwal derives its name from the fifty two forts, ‘garhs,’ that had come together to form a loose confederacy. 

Cities of Uttranchal
Uttarkashi       Pouri Garhwal Chamoli
Tehri Garhwal Pithoragarh     Almora
Dehradun        Rishikesh         Haridwar