I think the wording is intentionally vague these days. There used to be a limit in how long your leader could be.
CATCH AND RELEASE FLY-FISHING ONLY • Open to fishing year-round. • Fishing is permitted on a 24-hour basis. • No trout may be killed or had in possession. • Fishing may be done with artificial flies and streamers constructed of natural or synthetic materials, so long as all flies are constructed in a normal fashion with components wound on or about the hook. Fishing must be done with tackle limited to fly rods, fly reels, and fly line with leader material of monofilament line attached. Anything other than these items is prohibited. • Taking baitfish or fishbait is prohibited. • Wading is permitted unless otherwise posted. • An angler in a boat may possess bait and fish caught in compliance with the seasons, sizes, and creel limits in effect for a water from which it was taken, provided that the boat angler floats through the Catch and Release Fly-Fishing Only area without stopping or engaging in the act of fishing or the boat angler puts in or takes out his boat at an access point within the Catch and Release Fly-Fishing Only area. • A current trout permit is required.