Related Clues:
- Creators of artificial lakes
- Trenches in 42 Down
- Hydroelectric projects
- Beaver-made barriers
- Certain Colonial-era protectors
- Civil engineering projects
- Animal park rings
- Hydroelectricity projects
- Lake makers, at times
- Keeps from running
- Animal park barriers
- James Gardiner and Bill Bennett constructions
- Ditches old bird on way back
- Beavers' prides
- Sources of some electricity