| Geyser | 1975-12-21 |
|---|---|
| Depression | 1350 |
| Grand | 1401 |
| Lone Star | 1140 |
| Old Faithful | 0857 long, 1010 long, 1128 short, 1233, 1349 long, 1502 short, 1714 long |
| Riverside | 1100, 1647 |
| Values for Old Faithful Area | 1975-12-21 |
|---|---|
| Astronomical Twilight Begin | 06:10 |
| Nautical Twilight Begin | 06:46 |
| Civil Twilight Begin | 07:23 |
| Sunrise | 07:56 |
| Sunset | 16:46 |
| Civil Twilight End | 17:19 |
| Nautical Twilight End | 17:56 |
| Astronomical Twilight End | 18:31 |
| Moon Illumination | 91.66% |