| Geyser | 1981-12-11 |
|---|---|
| Graceful | 1800 |
| Values for Old Faithful Area | 1981-12-11 |
|---|---|
| Astronomical Twilight Begin | 06:04 |
| Nautical Twilight Begin | 06:39 |
| Civil Twilight Begin | 07:16 |
| Sunrise | 07:49 |
| Sunset | 16:43 |
| Civil Twilight End | 17:16 |
| Nautical Twilight End | 17:53 |
| Astronomical Twilight End | 18:28 |
| Moon Illumination | 99.99% |