Mirabilite Spring Mounds At The Great Salt Lake State Park

A very rare phenomenon is occurring on the shores of The Great Salt Lake in the Great Salt Lake State Park. Mirabilite Spring Mounds a very rare phenomenon that involves springs bringing up mirabilite from beneath the surface during freezing conditions which create really fascinating salt terraces. We came out to see these just about a month ago, but I wanted to see this rare phenomena at least one more time before they dissolve. This was the 2nd year it occurred so it could happen again, or, it might not happen again for a very long time, or ever again at all. So yeah I wanted to come see them again.

Quick Details:

Length: About 6/10 of a mile out and back depending how much wandering you do.
Trail Type: Out and back.
Difficulty: DR3 Its mostly flat, but walking on beach sand and mud.
Elevation Gain: Not much, about 19 feet.
Restroom: There is one in the Visitor Center and one at the marina as well.
Dogs? Yes, leashed.
Other Info: Fee Area. $5.00 per car. Waterproof boots recommended.

To Get Here:

Take i80 to exit 104. Head north. Turn left in front of Saltair. Continue down the narrow rd. to the fee station.

The mounds are on Silver Sands Beach, behind the visitor center.

The snowy mountains (Passenger Seat Photography (PSP)). There have been a lot of avalanches already this weekend so we decided we definitely didn’t want to go too high today.

The Trail:

Oh look, the little unnamed creek is flowing again.

Closer.

Before long we reached the mounds. Here is the main middle one. If the main 4th mound ever happened, there is no evidence of it.

A quick overview of what is going on here. There is a layer of mirabilite underground here. There are some natural springs coming up and bringing the mirabilite up to the surface. The cold weather is allowing it to crystalize and form these terraces. Once it warms up the mirabilite will break down into a powder called thenardite that is definitely not as interesting. So quick note, even if it were not illegal to take a sample, there isn’t a point to it. It will not hold it’s shape. I go into a little more depth from our first visit.

Looks like it has dried up. I might have missed the peak time for them, but I can still enjoy the structures.

With the lake being lower this year, the main mound was able to sprawl out quite a bit more, and has stayed that way.

The eastern mound.

Sad. They had to add a sign saying not to step on the formations.

I am almost certain that is a new mound to the left there.

Antelope Island. The lake is a pretty color today.

The back side of the eastern mound.

With the new little mound.

Nearing the front again. Oi. Look at that shoe print. That is completely disrespectful. Even if you don’t know what is going on here, it is obviously something special. To just, step on it. Oi.

What is this? There appear to be a couple new mounds just forming.

I did learn the springs can get clogged and just find new ways up to the surface, so I wonder if that is what happened here.

Back side of the middle mound.

Crystals.

The terraces are super cool. But I liked them a bit better with water running down them.

The western mound is kind of meh. It seems to have mostly broken down into the thenardite.

All three mounds.

The middle mound and the Kennecott Smelter Stack.

The middle mound is definitely the most interesting one.

The terraces are amazing. I say this every time, but they remind me of the terraces you can see at Mammoth Hot Springs in Yellowstone. Similar process, but with the big difference of temperature.

The middle mound from the west.

From the ‘front’ or south.

I find it interesting that it formed a fairly similar shape as it did last winter, except that it was allowed to skirt out more with the lake being lower.

More of the terraces.

Saltair 3. It currently exists as a concert venue, which is neat, but I would love to see it reconverted to the original glory it once was as a fun beach resort.

Still at the middle mound.

Back to the eastern mound. You can see the shoe print closer here. As well as some of the more intricate terraces.

Closer look.

The front of the eastern mound.

The middle mound again.

The top of the mound.

Terraces below.

The western mound again.

I finally managed to tear myself away from these amazing formations and hoped to seek out the old boat wreckage that was revealed after a storm last year.

Crossing the unnamed creek again.

Antelope Island again.

Beach creeks are so weird. Seems it would be easiest to join the lake here, but it goes on parallel to it instead.

Antelope Island.

Stansbury Island.

Hrm. well, we didn’t find the boat wreck. Either it wasn’t where I thought it was, or it has been retaken by the lake.

Looking back towards the mounds.

The last few times we came out here, I thought these were the stupid, useless, and often confusing and often dangerous “instagrammer cairns” as I call them. Turns out the park actually builds these for the orb weaver spiders. They act as condominiums for them. Kind of neat!

Side note: Normally rock piles like this, referred to as cairns are way markers, and help people keep on the trail where trails can be hard to pick up (think slick rock areas). However, in recent years instagrammers have thought they are a ‘fun’ way of adding something to their pictures. Which, as I said can be dangerous for people trying to find their way. As  mentioned, these ones are different.

The Kennecott smelter stack, and it is not producing any smoke. I think this is a first for me.

Well, that was fun. I am glad we got to see the spring mounds again before they disintegrate. We actually got them to ourselves again! I was a little bit worried we showed up at a time they might have done a tour, but that was not the case today. I think they are about done for the season, so I am glad we decided to come and check them out again. Super neat, super rare phenomena. 10 out of 10 squirrels. Of course, this was a little bit of a short adventure, so we decided to check out Sunset Beach out to Black Rock.

As for difficulty, it is short, but it is on beach sand, and there is a short steep incline. DR3.

Dogs are allowed, but must be leashed. Please clean up after your furry friends, and be sure that they are not damaging the fragile formations.