Where to Find and Catch Kyurem
From Pokemon Go Wiki
Kyurem are found and captured in Nest and Habitat locations.
Nests
Kyurem Nests are locations that consistently spawn Kyurem.
Habitats
Kyurem Habitats are spawn locations where Kyurem is likely to be encountered, but not guaranteed the way a Nest is.
Additional Tips and Information
Best Nests
If you know a really good nest or any of the nests above is really good, list them here: