The province of Qinghai is a remote region of north-west China with a population of about five million.
Although it has areas of industry around its major population centres - notably the capital Xining - most people make their living in agriculture.
Goat tracks are a more common sight than major highways, however, the Lanzhou-Qinghai and Qinghai-Tibet railway lines run through the province.
Qinghai borders the Xinjiang region to the north-west and Tibet on its south-west and much of the province is desert.
On average it is more than 3,000m (10,000ft) above sea level.
The epicentre of the earthquake that struck on 14 April is about 50km (31 miles) west of Jiegu, the main town of Yushu county, about 800km away from Xining.
Yushu is a prefecture within Qinghai which has limited autonomy because of its heavily Tibetan population.
It has a population of about 280,000 over a vast area of 267,000 sq km (103,000 sq miles). The population is 97% Tibetan.
Correspondents say China's strict rule over its restive Tibetan population may have meant a high number of troops stationed around Yushu when the quake struck, and the first images from the scene showed military personnel scrabbling to help the injured.
Yushu's high altitude - 4,000m - has posed problems for earthquake survivors and rescue teams.
Those whose homes lie in ruins face freezing temperatures at night, while the thin air makes conditions difficult for those trying to help.
One rescuer, Yang Xuesong, said the altitude was his biggest concern.
"This is the highlands. I don't know if the search dogs can get used to it," he said.
Yushu county has one airport - Batang - which was opened last year.
Chinese media said communications with the airport were lost after the quake and that roads to the terminal had been damaged.
Relief flights have been arriving at the airport in Yushu county
Flights later resumed, but as the small airport has no refuelling supplies, planes had to carry extra fuel which reduced the amount of supplies they could carry, state media reported.
The region has a long history of earthquakes. In 1927 an 8.6 magnitude tremor centred on Xining caused about 200,000 deaths.
In 1990 Qinghai was hit by a quake that left 126 dead and in 2006 Yushu county suffered a 5.6-magnitude earthquake that caused no reported casualties.
Despite being the source of several major rivers - including the Yangtze - Qinghai has suffered from soil erosion, water shortage and deforestation over the years.
Ethnically, Han Chinese account for about 55% of the population, while Tibetans make up about 21% and Hui 16%, according to estimates.
The Qinghai region was incorporated into China at the beginning of the 18th century, and became a Chinese province in 1928.
For centuries Qinghai was part of Tibet, and Tibetan nationalists still regard the province as under colonial rule.
Tourist attractions are relatively few in the province, although the huge saltwater Qinghai Lake - the largest in China - attracts thousands of visitors every year.