"Question:
What exactly is trout opener?"
Opening season for trout prut near everwhere in Pa.
"Are there resident rainbows or browns in the Elk that people can now fish for?"
No fishing for 32 hours before the opener tomorrow (sat 14 April) at 8am.
As 92 mentioned, no resident trout in Elk.
Too warm in the summer.
I haven't been across the boarder in a month or more, but from past years experience, the "residents" at this time of year in Elk are tired, beat up, moldy hold over steelies, thousands and thousands of smolts (little rainbows that will head out to the lake to grow up to be steelies), some fresh jacks (young steelies) might get lucky and pick a up a few fresh Ohio or NY steelie strays that got lost, truck loads of small Browns they just dumped in for the opener tomorrow.
Oh, and mucho suckers too
"What is the differance between trout and steelhead in the eyes of the DNR "
nothing, a Rainbow and steelie are the same
There are some different regs specific to the Erie tribs, though.
"(not sure what the fish and wildlife police are called in PA) "
Pennsylvania Fish and Boat Commision
"I heard they stock trout specifically for opener."
you heard right
Here's some info on regs
http://www.fish.state.pa.us/fact_fast_trout.htm If you don't mind sharing, where are you traveling from?
..L.T.A.