| Geyser | 1991-08-15 |
|---|---|
| Black Pool | 1153 |
| Echinus | 0943, 1057, 1154, 1200, 1255, 1358, 1507 |
| Morning | 0232 E, 0616 E, 0930, 1348, 1718, 2052 |
| Values for Old Faithful Area | 1991-08-15 |
|---|---|
| Astronomical Twilight Begin | 04:32 |
| Nautical Twilight Begin | 05:15 |
| Civil Twilight Begin | 05:54 |
| Sunrise | 06:25 |
| Sunset | 20:29 |
| Civil Twilight End | 21:01 |
| Nautical Twilight End | 21:39 |
| Astronomical Twilight End | 22:22 |
| Moon Illumination | 30.7% |