The container is a medium-sized tube. The cache is not under the bridge.
BACK CREEK #2 (Hoyt Station)
Route 2, Exit 306, Route 7 south for 8.5 km (5.2 mi.), Exit 29, Broad Road for one km (0.6 mi.), turn left on Branch Road for 16.2 km (10 mi.), Route 101 south for seven km (4.4 mi.), on to Hoyt Station Road. Built-in 1936. Length 28.8m (94' 4")
Congrats to Hades917 for FTF.