Related Clues:

• Challenge for salmon
• Glen Canyon, for one
• Mother very angry rolling round
• Crazy returning an animal's mother
• Flow obstruction
• Retaining barrier
• Something to do to teeth
• Grand Coulee ___
• Clean teeth with string
• Something you do for your teeth
• What a beaver may build
• Teeth-cleaning string
• Beaver's pride
• Brush your teeth and ___
• Beaver's water barrier