Yes. Bikers in Nevada are required to use hand signals before turning unless either:
the bike is in a designated turn lane; or
it would be unsafe to take a hand off the handlebar
Bicycle action in Nevada
Required hand signal
Left turnHand and arm extended horizontally Right turnHand and arm extended upward Stop or decrease speedHand and arm extended downward Reentering a traffic lane from a parked positionHand and arm extended horizontally.