| Geyser | 1999-10-26 |
|---|---|
| Grand | 0520 E, 1644 E |
| Great Fountain | 0427 E, 1344 E |
| Values for Old Faithful Area | 1999-10-26 |
|---|---|
| Astronomical Twilight Begin | 06:15 |
| Nautical Twilight Begin | 06:48 |
| Civil Twilight Begin | 07:22 |
| Sunrise | 07:52 |
| Sunset | 18:22 |
| Civil Twilight End | 18:51 |
| Nautical Twilight End | 19:25 |
| Astronomical Twilight End | 19:59 |
| Moon Illumination | 97.27% |