it is hard to say for sure, but i would lean toward summer fish. Hatchery summerrun spawn timing is earlier than hatchery winterrun by a few weeks and so egg developement should be getting close for at least some if not most summerruns now. The number of summerruns way outweighs the number of winterruns at this time of year in most systems, and lastly, your fish isn't nearly as chrome as i would expect a winterrun hen to be at this time of year. It could be, but my guess is summer fish. Nice one though for sure!