How can a lake be a salt water lake?

Answer 1

There is a channel....a opening where the salt water can enter

An inland lake can also be salty if mineral deposits under the lake contain salt, or the lake has only inflowing water and no out-flowing water. Overtime the inflow will bring minerals into the lake, without a way for the water to exit the lake, the waters of the lake will evaporate naturally, leaving the deposited minerals, increasing the water's salinity.

Answer 2

Salt lakes have salts and the Great Salt Lake is an important example.