From the plaque:
From this spot may be seen
a portion of the world-renowned Loop completed in 1876
under the direction of William Hood, Southern Pacific
railroad engineer. In gaining elevation around the central
hill of the Loop, a 4,000-foot train will cross 77 feet
above its rear cars in the tunnel below.
Dedicated October 25, 1953. Marker placed by Kern County Historical Society, Bakersfield Parlor No.42 N.S.G.W., El Tejon Parlor N.D.G.W., Kern County Museum, Southern Pacific Railroad.