It is over 60 kilometres (37 mi) wide from west to east, stretching from the highway between Mount Barker and Cranbrook eastward past Gnowangerup.

The mountains are formed of metamorphic rock derived from quartz sandstones and shales deposited during the Paleoproterozoic Era, between 2,016 and 1,215 million years ago (based on U-Th-Pb isotope geochronology of monazite crystals).

Despite the relative youth of the mountains, the soils remain very poor, creating the species-rich heathland flora.

The branch of the Kalgan River that forms the southwestern border of the park is fed in large part from precipitation falling in the western half of the range.

Most rain falls between May and August, with summer being very frequently completely dry around Borden for over a month and having typically very light showers in the south and on the peaks.

[7] The plains in the Stirling Range region were the hunting grounds for small groups of Indigenous Australians for thousands of years before European settlement.

The Stirling Range played an important role in their culture, appearing in a number of Dreamtime stories.

[14] Late in 1835, Governor James Stirling and John Septimus Roe led an expedition from Albany to Perth.

[17] Notable features include Toolbrunup, Bluff Knoll (the tallest peak for a thousand kilometres or more in any direction and most popular tourist attraction), and a silhouette called The Sleeping Princess which is visible from the Porongurup Range.