| Geyser | 1979-07-31 |
|---|---|
| Bear Den | 1035 |
| Constant | 0955, 1318, 1400 |
| Dark Cavern | 1050 |
| Echinus | 1027 |
| Little Whirligig | 0905, 1000, 1303 ie, 1405 |
| Whirligig | 1045 |
| Values for Old Faithful Area | 1979-07-31 |
|---|---|
| Astronomical Twilight Begin | 04:04 |
| Nautical Twilight Begin | 04:53 |
| Civil Twilight Begin | 05:35 |
| Sunrise | 06:08 |
| Sunset | 20:50 |
| Civil Twilight End | 21:23 |
| Nautical Twilight End | 22:06 |
| Astronomical Twilight End | 22:54 |
| Moon Illumination | 40.25% |