Bluff Branch Line runs from Invercargill to Bluff. Bluff used to be called Campbelltown until 1917.
The Otago Provincial Council in 1859 approved the construction of a road to Campbelltown (Bluff). The builders were beaten by the swamp.
Southland Provence split from Otago in1861 and an alternative to road was considered in 1862.
The creation of a harbour and rail was started. The rail line was one of the first in NZ and opened 1867.
This bridge location can be confusing. Some people call it Duck creek, others Waimatua Creek. Such confusion made it onto the NZ Topo maps.
Here it is named Waimatua or Duck Creek.
There are more Rail bridges on this line but this one is built on the tressle bridge style.
I hope the confusion does not follow to make the success of your find difficult.
Best to find when travellling North, towards Invercargill. Parking either end of Road Bridge but best on the South end.
Bluff road is a busy piece of road so keep away from it when out of your caching machine.
Difficulty rating due to presence of white bait fishermen who may be in the area seasonally dipping their nets as there was when placed.
You do not need to go anywhere near the rail bridge or rail line.