Trains passed regularly through the railroad tunnel through Missionary Ridge for over 90 years. However, by 1950, larger railroad equipment was having difficulty getting through the narrow tunnel.
Equally as important, the tunnel had a single track where by then a double track was needed for the heavy rail traffic.
The railroad began searching for a new route to replace the old East Tennessee line.
The Western and Atlantic had skirted the end of the ridge, though it involved several crossings of South Chickamauga Creek.
It was decided to position the new East Tennessee bypass route not far from the W&A, but across the creek to avoid the bridges.
A route was chosen that moved away from the old Cincinnati Southern line in East Chattanooga at the old King's Point community.
It was built on a hill with a treslle across Harrison Pike, then another over busy Bonny Oaks Drive.
The line went above Youngstown Road and then trestled over Lightfoot Mill Road. Just below this trestle at the bridge over South Chickamauga Creek can be seen a bridge crossing for a W&A spur line going toward Tyner and then, behind it, the original East Tennessee line crossing the creek. That is part of the section now used by the Tennessee Valley Railroad Museum for daily excursions that go through the historic tunnel.
From this creek view at Lightfoot Mill Road, one of the original piers for the East Tennessee line that was later replaced can be seen beyond the newer East Tennessee crossing.
The bypass then crossed over the spur of the W&A before joining the old East Tennessee line near the present Railroad Museum.