| Geyser | 1991-07-17 |
|---|---|
| Echinus | 1535 |
| Gray Lakes | 1200 |
| Values for Old Faithful Area | 1991-07-17 |
|---|---|
| Astronomical Twilight Begin | 03:38 |
| Nautical Twilight Begin | 04:34 |
| Civil Twilight Begin | 05:19 |
| Sunrise | 05:54 |
| Sunset | 21:04 |
| Civil Twilight End | 21:39 |
| Nautical Twilight End | 22:24 |
| Astronomical Twilight End | 23:19 |
| Moon Illumination | 35.76% |