MORTON VALLEY, TEXAS. Morton Valley, on Farm Road 3363 near State Highway 69 north of Interstate Highway 20 in northern Eastland County, was settled in the 1880s and increased in size during the oil boom of 1917-25. In 1921 the Morton Valley school was established as a consolidated education center for three surrounding districts. In 1940 the population of Morton Valley was forty, and in 1980 through 2000 it was forty-six.