In over 30 years of FFing in PA I have only had one trout go into my backing (a 21" brown, Yellow Breeches, 1985). In this state, the only fish that will consistently pull into backing are big river carp. I'd imagine some steelhead in heavy flows will do it pretty easily. Guys who fish the upper Delaware for wild rainbows with fine tippet and soft set clicker drags probably see backing on occasion too.
In northest saltwater fishing, false albacore will go there. Stripers and bluefish usually won't. Seeing backing is much more common in Florida. In addition to tarpon, other inshore fish that will almost always do this include bonefish, permit, jacks, large cudas, large redfish, and sharks over 3' long. Beware the stories about fish taking "hundreds" of yards of backing. I think in most cases these are exagerrations or fishermen who simply don't know how to fight a fish. I've never had a bonefish take what I think is more than maybe 75 yards of backing. If you've got over 200 yards of backing you should never get spooled (as long as you can follow the fish).
The famous salt FFer, Chico Fernandez (who catches a LOT of flats species every year) did an experiment with backing marked at 100 yards. After over a year of fishing and many fish caught (including tarpon and dolphin), he finally hooked a large shark over 100 lbs that pulled the backing past the 100 yard mark. The common claim that bonefish routinely run over 300 yards is bunk.
In northest saltwater fishing, false albacore will go there. Stripers and bluefish usually won't. Seeing backing is much more common in Florida. In addition to tarpon, other inshore fish that will almost always do this include bonefish, permit, jacks, large cudas, large redfish, and sharks over 3' long. Beware the stories about fish taking "hundreds" of yards of backing. I think in most cases these are exagerrations or fishermen who simply don't know how to fight a fish. I've never had a bonefish take what I think is more than maybe 75 yards of backing. If you've got over 200 yards of backing you should never get spooled (as long as you can follow the fish).
The famous salt FFer, Chico Fernandez (who catches a LOT of flats species every year) did an experiment with backing marked at 100 yards. After over a year of fishing and many fish caught (including tarpon and dolphin), he finally hooked a large shark over 100 lbs that pulled the backing past the 100 yard mark. The common claim that bonefish routinely run over 300 yards is bunk.