More about the Family of Frank Thomas and Elvira Rowntree can be found in Burnet County HIstory, Vol II, page 314. 
He lived in the Spring Creek Community, about 5 miles west of Burnet.    He was appointed as a member of the first School Board of Trustees in 1885.  (Burnet County History, Vol I, pages 133 and 148)

Frank Thomas served in the Confederate States Army,
Co. B, 21st Texas Cavalry

More information in Civil War Sketches

He died 17 April 1916 and is buried in the Odd Fellows Cemetery in Burnet.
Photo from Find A Grave, Memorial #30588546
Photo posted by Anonymous

Elvira Rowntree Thomas Obituary

See also Descendants of James L. Rowntree