Sharon Lee Mcgrath, Age 12, Of Feeding Hills, Mass., for her question:

How did the salt get in the great Salt Lake?

You can sit in the lake with your head and shoulders above the water. You can float with your toes in the air. In fact, you cannot sink yourself in utah's great salt lake. This is because the water is so full of dissolved salty chemicals.

Salt water, you might think, belongs in the seas, and it is strange to find a lake of saltier than sea water way out in the desert of northern Utah. The waters of the great salt lake, it is estimated, contain about six times more salty chemicals than normal sea water. Yet the geologists tell us that this was once a fresh water lake.

The size of the salty lake varies with the seasons, but, on the average, it is about 50 miles wide and 75 miles long. This is as large as Lake Huron, but the ancient lake of utah was 10 times this size. We have named it lake Bonnevine, and thousands of years ago it glistened with sparkling fresh water.

Lake Bonneville stayed fresh, because its waters drained through the snake and columbia rivers into the pacific ocean. Later the geography changed, and this outlet to the sea was sealed off. The streams and rivers brought less and less water into the lake, and the area shrank.

The so called fresh water of the rivers has but a fraction of the salty chemicals found in sea water. But some chemicals are disso1ved and carried away by every strebm that runs over the ground. Through the ages, the drying lake bonneville gathered more and more of these chemicals and had no way to empty its salty waters into the sea. Finally it became the great salt lake, which is getting saltier with every season.

Water evaporates from the surface of the great lake, especially in the warm simnmer. In the process, liquid water becomes gaseous vapor and molecules of water beccme m01ecules of gas which float up to join the other invisible gases of the air. But the dissolved chemicals are not changed into gases. So the water evaporates and leaves them behind.

You can still find some of the shores and beaches of old Lake Bonneville, far from the great salt lake. There are also sparkling white salt flats where the old lake gradually shrank and disappeared, leaving its load of glistening chemicals lying on the ground there are several islands in the great salt lake, and it is no surprise to learn

That they have beaches with sand. Herons and pelicans, gulls    and cormorants nest on these islands.     The biggest is antelope island where there is grass enough for sheep and cattle, plus a herd of buffalo. The lake supports a blue green algae, brine shrimp and the grubs of certain water flukes, but no fish live in its salty waters.