Mount Gay-Shamrock is a census-designated place (CDP) in Logan County, West Virginia, United States.
Mount Gay-Shamrock has a 2020 population of 1,360. Mount Gay-Shamrock is currently declining at a rate of -2.51% annually. The population was 1,779 at the 2010 census.
A post office was established as Mount Gay in 1916.
Geography
Mount Gay-Shamrock is located in west-central Logan County, and the village of Shamrock just to the west in the valley of the Copperas Mine Fork. Settlements in the CDP run south up the valley of Island Creek, southwest up the valley of the Copperas Mine Fork, and west up the valley of the Mud Fork. The CDP is bordered to the east by the city of Logan, the county seat, and to the west by U.S. Route 119, a four-lane freeway which separates Mount Gay-Shamrock from Verdunville.
West Virginia Route 73 is the main road through the CDP, following the valley of the Mud Fork and connecting US-119 to the west with Logan to the east. West Virginia Route 44 leads south from Mount Gay up the valley of Island Creek. Old US Highway 119 runs up the valley of the Copperas Mine Fork, joining current US-119 at Holden.
According to the United States Census Bureau, the CDP has a total area of , of which , or 0.15%, are water.