| Geyser | 1966-08-20 |
|---|---|
| Cistern Spring | 0800 |
| Ebony | 1420 |
| Echinus | 0801, 0909, 1017, 1123, 1230, 1340, 1447, 1554, 1704 |
| Harding | 1030-1320 |
| Ledge | 0600 A |
| Scummy Pool | 1800 |
| Steamboat | 0800-1800 |
| Values for Old Faithful Area | 1966-08-20 |
|---|---|
| Astronomical Twilight Begin | 04:41 |
| Nautical Twilight Begin | 05:22 |
| Civil Twilight Begin | 06:00 |
| Sunrise | 06:31 |
| Sunset | 20:21 |
| Civil Twilight End | 20:52 |
| Nautical Twilight End | 21:30 |
| Astronomical Twilight End | 22:11 |
| Moon Illumination | 19.75% |