Mountain Valley was a religious community twelve miles south of Bandera on the Medina River in northern Medina County. Led by Lyman Wight, a group of about 150 members of the Reorganized Church of Jesus Christ of Latter Day Saints moved to Texas in 1845. Before they established Mountain Valley on the Medina River in the fall of 1854, the group had settled in various locations in the Texas Hill Country, among them a site six miles above Austin on the Colorado River, at Zodiac on the Pedernales River, and on Hamilton Creek in Burnet County. The community apparently thrived from 1854 until sometime in 1858, when Indian raids, pressure from creditors, fear of the impending Civil War, and, most importantly, the death of their spiritual leader Lyman Wight, resulted in the abandonment of the settlement. Mountain Valley likely had a grist and saw mill and a temple of worship during its four years of existence. Its site was inundated by the Medina Dam project in 1913. A Texas Historical Commission marker on Medina Lake Dam near Mico, Texas, details the history of the colonists of Mountain Valley.