In its heyday (1400-1600), The Kingdom of Lo dominated the Kali Gandaki River trade between India and Tibet. By the 18th century Lo had lost control over this trade and had been incorporated into the modern Kingdom of Nepal. Isolated deep in the Himalaya, Lo's heriditary rajas retained most of their feudal powers and the area remained closed to the outside world until 1991. In the spring of 1992, author Peter Matthiessen and correspondent-photographer Thomas Laird traveled deep in the secret valley of Sao Kohla, tucked high in the northernmost reaches of the Himalaya. They were the first Westerners to venture there in thirty years. Matthiessen's expansive narrative and Laird's poignant photographs reveal a place where mountains five miles high cast their shadows over the deepest canyon in the world; where 150-million-year-old fossils rise to the light of day at 13,000 feet; and where mountain nomads spend their lives herding their flocks across desolate slopes and through desert valleys, "utterly lost in the eternal earth and air".