The two geysers at the end of the Fairy Falls trail are Spray and Imperial Geysers. The first one you encounter is Spray (apparently, before the fires it was somewhat hard to find, but now, you can almost see it from Fairy Falls) To get there, you just hop over Imperial Geyser's runoff (Which I must say is probably one of the most impressive in the park - note the formations and growth in it. It is especially odd because it runs through the forest like a stream, but looks exactly like geyser runoff!!). Back to Spray - it is a geyser with several openings. Lately, at least one of these openings is active at all times. Heights range from a few inches to almost 20 feet. The openings cycle through their activity so you have to stay a few minutes to see all of them play.
Then, head on up to Imperial Geyser. The large blue pool is Imperial and hasn't been active for several years. The activity you will see is from an opening on the edge of the blue pool (I don't believe it has been given a name unless the name Imperial has been transfered to it). The activity is constant with some bursts reaching nearly 50 feet. Be sure to check out the mudpots here - they are very cool!!
The two hills behind Imperial are the Twin Buttes. They were formed when glacers encountered a large hot spring (or at least very intense hot spring activity) where the Buttes sit now. The glaciers melted and deposited all their till in the form of the Buttes. I suppose that it is also possible that glaciers already covered the area when a mini sort of Jokulhops occured underneath the glacier in the form of a large steam explosion. The activity of Imperial and Spray Geysers is the evidence of the springs underneath the Buttes. If you notice there are fumaroles at the top of one of the Buttes. This means that there is still very intense geothermal activity underneath if it is great enough to push the steam to that elevation. On top of the other Butte you will find lily pad lakes that sit in old hydrothermal explosion craters - more evidence of intense activity underneath.
