| Geyser | 1981-07-19 |
|---|---|
| Arsenic | 1103 |
| Dark Cavern | 1446 |
| Echinus | 1100, 1255, 1335, 1428, 1449, 1548 |
| Giantess | 1057 |
| Valentine | 1058 ie, 1925 A |
| Veteran | 1128 |
| Whirligig | 1124, 1244, 1831 |
| Values for Old Faithful Area | 1981-07-19 |
|---|---|
| Astronomical Twilight Begin | 03:43 |
| Nautical Twilight Begin | 04:37 |
| Civil Twilight Begin | 05:21 |
| Sunrise | 05:56 |
| Sunset | 21:02 |
| Civil Twilight End | 21:37 |
| Nautical Twilight End | 22:22 |
| Astronomical Twilight End | 23:15 |
| Moon Illumination | 95.47% |