| Geyser | 1991-08-16 |
|---|---|
| Blue Mud Steam Vent | 1200 |
| Echinus | 0918, 1017, 1120, 1224, 1330, 1433, 1532 |
| Emerald Spring | 1200 |
| Morning | 0728, 1100, 1457, 1855, 2230 |
| Yellow Funnel Spring | 1200 |
| Values for Old Faithful Area | 1991-08-16 |
|---|---|
| Astronomical Twilight Begin | 04:34 |
| Nautical Twilight Begin | 05:17 |
| Civil Twilight Begin | 05:55 |
| Sunrise | 06:27 |
| Sunset | 20:28 |
| Civil Twilight End | 20:59 |
| Nautical Twilight End | 21:38 |
| Astronomical Twilight End | 22:20 |
| Moon Illumination | 40.46% |