| Geyser | 1975-12-31 |
|---|---|
| Castle | 1230 ie |
| Grand | 1118 |
| Lion | 1033, 1305, 1429 ie |
| Old Faithful | 0936 long, 1052 short, 1150 long, 1311 long, 1424 short, 1509 long |
| Values for Old Faithful Area | 1975-12-31 |
|---|---|
| Astronomical Twilight Begin | 06:14 |
| Nautical Twilight Begin | 06:49 |
| Civil Twilight Begin | 07:26 |
| Sunrise | 07:59 |
| Sunset | 16:52 |
| Civil Twilight End | 17:26 |
| Nautical Twilight End | 18:02 |
| Astronomical Twilight End | 18:38 |
| Moon Illumination | 2.01% |