Yes — Oregon rule OAR 333-060 requires an available telephone capable of emergency dialing.
Oregon requires the emergency telephone to be available and capable of dialing for emergency services.
Citation: OAR 333-060
Oregon's language focuses on functionality over exact placement, so the main compliance concern is making sure the unit works and can complete a call to 911 without any extra steps.
SouthEast Telephone installs and monitors cellular emergency pool phones nationwide and can help you meet Oregon's requirements.