The Elburz Range forest steppe ecoregion is an arid, mountainous 1,000-kilometer arc south of the Caspian Sea, stretching across northern Iran from the Azerbaijan border to near the Turkmenistan border. It covers and encompasses the southern and eastern slopes of the Alborz Mountains as well as their summits. The Caspian Hyrcanian mixed forests ecoregion, with its lush green mountainsides and plains that receive moisture from the Caspian Sea, forms this ecoregion's northern border. The vast Central Persian desert basin ecoregion forms its southern border. The Alborz range is composed of a granite core overlain with sedimentary rock including limestones, shales, sandstones, and tuffs. Metamorphic rocks such as schists, marbles, and amphibolite are also widely found. The climate is arid with annual precipitation varying from 150 mm to 500 mm, falling mostly as winter snow.