| Clue | Source | Date |
|---|---|---|
| Line through the Rocky Mountains | Newsday | 28 Jun 2023 |
| The Rocky Mountains | Wall Street Journal | 26 Jun 2023 |
| Rocky Mountains line | Newsday | 13 Jan 2019 |
| Passage between life and death | New York Times | 21 Apr 2018 |
| Passage between life and death | ||
| Significant difference | Newsday | 30 Nov 2016 |
| Terrific space between? | ||
| Passage from life to death | ||
| Significant difference | ||
| Rocky Mountains line | ||
| Rocky Mountains line | ||
| Rocky Mountains line | ||
| Rocky Mountain watershed | ||
| U.S. watershed | ||
| Rocky Mountains. | ||
| Continental backbone. | ||
| Watershed of the Rocky Mountains. |