The Rio Grande narrow gauge had a few people named Johnson in the engine service. I would need additional information to prove if they were related.
Louis Johnson was promoted to engineer on 6-15-1893. He was one of the engineers on the Silverton Branch train when fireman John Connor waas killed. Johnson was later killed on a similar wreck on the Silverton Branch.
D.R. Johnson was hired as a fireman on 1-25-1901 and promoted to engineer on 7-12-1905.
John ``Jughead'' Johnson passed his student trips on 8-30-1906 and promoted to engineer on 1-1-1910.
A.S. Johnson marked up as a fireman for the first time on 10-14-06 and promoted to engineer on 1-5-1910. He lasted into the diesel era, being the seniorengineer in Alamosa in the late 1950s.
J.W. Johnson's fireman's date was 9-15-1914. He was promoted to engineer on 10-20-1918.
The last of the Johnsons on my list was J. I. Johnson, who had a fireman's date of 10-19-1918.