sort of a GMC equivalent to the Silverado's Trail Boss guise. The current All Terrain package is available in three different tiers on the Sierra SLT: All Terrain, All Terrain SLT Premium and All ...

GMC has released a new off-road package for its Sierra half-ton. The Sierra All-Terrain X comes standard with a number of functional and style upgrades to help it head off-road and look good while ...

DETROIT – GMC today introduced the 2015 Sierra All Terrain HD, a refined, off-road-inspired execution of the brand's capability that blends exclusive design features with the versatility of 4WD ...

General Motors teased truck lovers by unveiling the All-Terrain HD Concept, an off-road, pre-runner inspired vehicle in the SVT Raptor idom and derived from the current GMC Sierra HD. At the time ...

This is a small but meaningful touch: it’s fun to be greeted with a topographical map animation when you start up the Sierra. Mt. Denali, the highest mountain peak in North America (elevation 20,310 ...