 The Ellensburg Basin, more formally called the Ellensburg Formation, holds nearly 4,000 feet of rock, sand, and gravel that accumulated over a period of 2 to 10 million years during the Miocene and lower Pliocene age.The climate at Thorp is hot during summer when temperatures tend to be in the 80s, and very cold during winter when temperatures tend to be in the 20s.The warmest month of the year at Thorp is July, with an average high of 77.2 °F and an average low of 51.8 °F.