MOAB, Utah (ABC4) — Have you ever flown over southeastern Utah, looked out the window saw the vivid shades of blue creating interesting shapes against the red rock?

It’s not a trick of the eye. Those are evaporation ponds for potash mines and you should steer clear of them.

While the brilliant blues against the dry red rock may look like a veritable oasis, perfect for your next post on Instagram, it’s not a place for recreation. The potash mines in Moab are similar to the striking blue water found in a canal near the Bonneville Salt Flats. Just outside of the city of Moab are 23 colorful ponds spread across 400 acres.

The Bureau of Land Management made a clear warning saying potash mines were for industrial use and not designed or safe for public recreation.

“Therefore, the public should not access, swim, float, kayak, canoe, or pursue any other recreation activities in these industrial canals,” BLM said about the Bonneville Salt Flats.

So how does potash mining work and why are they so vividly blue?

The waters use solar evaporation to mine potassium-containing salt out of the red rock. According to NASA, as the water evaporates, it leaves behind the salt deposits which eventually become potash ore.

The incredible picture-esque colors come from a dye that is put into the water to help reduce the amount of time it takes for the potash to crystallize. The color turns to a seafoam green color as it goes well into the evaporation process before becoming a tan color, showing it’s nearly done.

The entire process reportedly takes about 300 days.

Potash is primarily used as a fertilizer to help support plant growth, however, it has several other uses as well. According to Canada’s Department of Natural Resources, potash is also used in detergents, pharmaceuticals, de-icing salt and can even be included in the human diet.