Altoona's Horseshoe Curve

This image is of "Horseshoe Curve," which is a stretch of Norfolk Southern Railway's Pittsburgh Line near the site of the Altoona board track speedway and captured during the era of the track's operation in the 1920's. Construction on Horseshoe Curve began in 1950 and took three years to complete.
 
 Thanks to the Paul Sheedy Collection for this photo.