First opened to the public in October, 2005, Government Canyon State Natural Area (GCSNA) preserves 12,244 acres (49.5 km2; 19.1 sq mi) of rugged hills and canyons typical of the Texas Hill Country. It is designated a Natural Area, rather than a State Park, and therefore the primary focus is maintenance and protection of the property's natural state. Accordingly, access and recreational activities may be restricted if the Texas Parks & Wildlife Department (TPWD) deems such action necessary to protect the environment.

The reserve is located in northwestern Bexar County, and protects a large, relatively pristine tract of Hill Country terrain, numerous and diverse species of plants & wildlife, the upper Culebra Creek/Leon Creek watershed, and a critical aquifer recharge zone for the San Antonio Water System.[2]

In September, 2009, the City of San Antonio transferred 3,000 acres (12 km2) of land to the TPWD for inclusion in the Natural Area, specifically to support long-term protection of the Edwards Aquifer, and thereby increasing the total acreage within the reserve from 8,783 acres (35.54 km2) to 11,783 acres (47.68 km2). Most recently, in April, 2013, an additional 461 acres (1.87 km2) were added to GCSNA through a combination of funding from the City of San Antonio, Texas Parks & Wildlife, and a US Fish & Wildlife Service endangered species grant, which brought the reserve's total area to 12,244 acres (49.55 km2).