| Geyser | 1999-10-19 |
|---|---|
| Grand | 1156 E, 2353 E |
| Great Fountain | 0226 E, 1256 E, 2342 E |
| Values for Old Faithful Area | 1999-10-19 |
|---|---|
| Astronomical Twilight Begin | 06:06 |
| Nautical Twilight Begin | 06:40 |
| Civil Twilight Begin | 07:14 |
| Sunrise | 07:43 |
| Sunset | 18:33 |
| Civil Twilight End | 19:02 |
| Nautical Twilight End | 19:36 |
| Astronomical Twilight End | 20:10 |
| Moon Illumination | 65.82% |