Evening Primrose is found in the Sylvan Springs area of the Gibbon Geyser Basin. While headed north on the Grand Loop Road toward Norris you will see a small geyser basin to your left across Gibbon Meadows - this is Sylvan Springs. While once considered one of the most picturesque basins in the park, Sylvan Springs soon became highly acidic and sulferous. The pools became, you might say, "infected" with sulfer. (In fact some say that Evening Primrose used to resemble Morning Glory Pool. Now it is full of sulfer froth and not very attractive - unless of course, you like that sort of thing!)
Sylvan Springs is very difficult to get to mostly because, no matter what, you pretty much have to cross the marshy Gibbon Meadows. This requires some wading and some bushwhacking and will always end up with you soaked (even late into the season). There once was a maintained trail that led here (Breaking off where the Monument Geyser Basin trail heads up the hill) early in the century. But, alas, once the springs became grotesque, not enough intrest remained in this area. If you decided to go, try to find someone who has been there before and knows their way across Gibbon Meadows. Also, remember to be very careful when out there - retrieving an injured person from Sylvan Springs would not be an easy task!!!
Link to picture of Evening Primrose Spring
