| Geyser | 1981-08-04 |
|---|---|
| Arsenic | 1430 |
| Bear Den | 0806 |
| Blue | 1200 |
| Echinus | 0830 |
| Morning | 0445, 1113, 2353 |
| Pequito | 1200 |
| Rubble | 1730 |
| Veteran | 1211 |
| Whirligig | 0923, 1122, 1415, 1532 |
| Values for Old Faithful Area | 1981-08-04 |
|---|---|
| Astronomical Twilight Begin | 04:13 |
| Nautical Twilight Begin | 04:59 |
| Civil Twilight Begin | 05:41 |
| Sunrise | 06:13 |
| Sunset | 20:44 |
| Civil Twilight End | 21:17 |
| Nautical Twilight End | 21:58 |
| Astronomical Twilight End | 22:45 |
| Moon Illumination | 18.08% |