| Geyser | 1999-05-01 |
|---|---|
| Castle | 1129 E |
| Great Fountain | 0848 E, 2038 E |
| Values for Old Faithful Area | 1999-05-01 |
|---|---|
| Astronomical Twilight Begin | 04:18 |
| Nautical Twilight Begin | 05:02 |
| Civil Twilight Begin | 05:41 |
| Sunrise | 06:13 |
| Sunset | 20:27 |
| Civil Twilight End | 20:58 |
| Nautical Twilight End | 21:38 |
| Astronomical Twilight End | 22:22 |
| Moon Illumination | 99.64% |