Yes — Minnesota rule 4717.1250 requires the emergency phone to be accessible from the pool deck.
Minnesota requires the emergency telephone to be accessible from the pool deck area.
Citation: 4717.1250
Mounting the phone directly on the pool deck, rather than in a separate building, is the most straightforward way to satisfy Minnesota's requirement.
SouthEast Telephone installs and monitors cellular emergency pool phones nationwide and can help you meet Minnesota's requirements.