| Geyser | 1999-10-20 |
|---|---|
| Constant | 1035 |
| Grand | 1223 E |
| Great Fountain | 1029 E, 1946 E |
| Values for Old Faithful Area | 1999-10-20 |
|---|---|
| Astronomical Twilight Begin | 06:07 |
| Nautical Twilight Begin | 06:41 |
| Civil Twilight Begin | 07:15 |
| Sunrise | 07:44 |
| Sunset | 18:31 |
| Civil Twilight End | 19:01 |
| Nautical Twilight End | 19:34 |
| Astronomical Twilight End | 20:08 |
| Moon Illumination | 75.12% |