There was a river, on the other side of the river was a ............... How did he do that?

There was a river, on the other side of the river was a mango tree. One boy wanted to get one of those mango, there was not a boat, nor the boy knew how to swim. But he still went to the tree to get the mangoes.

How did he do that?

Solution -

The river was dry,means it has converted into ice form i.e. frozen