Bonnie Lake offers one of the most interesting geological paddles in all of Eastern Washington. The lake was formed nearly 15,000 years ago as the glacial Lake Missoula melted and filled the glacial lakes of Spokane and Columbia. The rapid increase in melt flooded the “scabland” and washed out the dirt around the cliffs you see today.
The most interesting part is the island in the middle of Bonnie Lake. This island is dated to 1.5 Billion years ago. The entire cliff range is only 15 Million years old. The fact that the water cleared these two diversely pieces of rock only 15,000 years ago is remarkable. It is worth the time to experience standing on rock that is 1.5 Billion years old.
