The only waters the Commission closes to fishing are the designated stocked trout waters which are closed from March 1 until the opening day of trout season. It is unlawful to fish in them for any species during that period of time.
The Commission does not prohibit fishing in other waters which contain wild trout even when it is unlawful to keep them. So it is not a crime to fish in those waters during the extended trout season.
However, the current regulations also do not specifically permit catch-and-release of wild trout during the time when they are out of season. This means that anglers who fish for trout in anything other than stocked trout waters or some specially regulated waters during the extended season could find themselves in violation of the law.
Here's how: The fishing regulations state that it is unlawful to catch fish except during their season. To protect those who may inadvertently catch a fish during the closed season, the regulations state that it is not a violation if a fish is caught during a closed season while legally fishing for another species if the fish is immediately returned unharmed to the water. This does create a strict liability standard: If the fish caught out of season is harmed or killed - even inadvertently - the fact that an angler says he is fishing on a catch-and-release basis is no defense.
Bottom Line: The current regulations are not intended to encourage fishing for any species during the closed season even on a "catch-and-release" basis, but it is not illegal to fish as long as the fish is immediately returned unharmed to the waters from taken. Anglers who target a fish during the closed season could potentially harm the fish and would then be liable for violating the closed season regulation.