The province of Sichuan suffered a catastrophic earthquake on May 12, 2008 centered on Wenchuan County, about 100km north of Chengdu city. Many cities were nearly completely destroyed and over 80,000 people are dead or missing with hundreds of thousands more injured or homeless. Government response was fast, but reconstruction will take years.
Many of West Sichuan's main attractions are located at altitudes above 3,000 meters and thus altitude sickness is a threat. Make sure to monitor your own health and take it easy for a day or two if moving from the low lands to higher elevations.
To help combat this sickness, many local Chinese eat medicine known as Hong Jing Tian. These are red capsules that the soldiers of the People's Liberation Army use to help them quickly adjust to altitude conditions in the Western Chinese provinces. Local tour companies will have a ready supply of this medicine if you ask.
There is also tension in Western Sichuan between the Chinese government and the mainly Tibetan people there and travel restrictions may apply to this area. See the warnings under Tibet.
talk
The native language of most of Sichuan is a variant of Mandarin Southwest, which differs from standard Mandarin of the north-east significantly in pronunciation, and use of slang which are unique to the area. Nevertheless, native speakers of Mandarin will be able to understand the local dialect albeit with some difficulty. Tibetan is still the mother tongue in most of the highland west, but the region becoming more and more Sinofied. There is a moderate amount of bi-lingual signage in the area. Therefore, many young people in the western regions are bi-lingual in both Tibetan and Mandarin or just speak Mandarin. Qiangic, native to the Qiang minority group, also native to Sichuan, can also be found in isolated parts of western Sichuan. The vast majority of signage is always in Mandarin Chinese characters throughout the province regardless of the ethnic majority in the given area albeit you will see some signage in Tibetan indic script. Many young people in Sichuan's larger cities speak some English.