All Game Fish--March 1-Nov. 30:

"Fly fishing only and use of motors prohibited Apr. 16-Nov. 30."

Does this mean (a) Fly fishing only from March 1 to Nov. 30, or (b) Fly fishing only from April 16 to Nov. 30? Grammatically, the "and" indicates the phrase "fly fishing only" is modified by "Apr. 16-Nov. 30", but I can't trust that the state hired grammarians to ensure easily readable regs. HELP!