Robbie and his family spent the week at a nearby mountain range. Â As Robbie hiked the mountains he made several observations. Â He noticed that as he hiked up to a higher elevation, the temperature became colder and it was raining. He noticed that there were many types of trees on this side of the mountain. As he crossed the mountain and hiked back down to the other side Robbie noticed that it was very dry and hot with very little trees. Â It almost looked like a desert.