About Southern Idaho

In this most unique area of Idaho,

our cities sit in an area formed by fire, wind and water. The mighty Snake River and its magnificent canyon etches the boundaries of southern Idaho communites where many falls, including 212 foot Shoshone Falls, can be seen. 



The region boasts a beautiful four-season climate. July averages 88 degrees with lows in the 50s while January temperatures range from 37 in the day to 21at night. The area receives about 11 inches of snow and 9 inches of rain annually and the air is dry and clear.


Many southern Idaho cities are in an area known as “the Magic Valley" after canals carried water from the Snake River to the desert soil to create productive farmland. Southern Idaho cities have long been agricultural centers with vast number of employers involved in food production, food processing, food science and support-related services.

The magnificent Snake River Canyon cuts into hundreds of feet of volcanic rock as a result of the ancient Bonneville Flood that occurred over 15,000 years ago.
This colossal flood began at ancient Lake Bonneville, a vast prehistoric body of water who’s only remains are the great Salt Lake and North Marsh Creek in Southern Idaho. The Bonneville flood was the second worst flood in the history of the world. The first was in Montana which was far more violent and dealt it’s wrath on Northern Idaho.

Lake Bonneville, with no outlet to the sea, covered over 20,000 square miles including most of Utah and eastern Nevada and reached into southern Idaho. Eventually, rainfall and glacier melt around the end of the Ice Age caused the interior basins of Idaho, Utah and Nevada to fill with water creating two huge lakes and many smaller ones. In addition, Bear River that once flowed into the Snake River was dammed due to a volcanic eruption and now flowed into Lake Bonneville, filling it even more. Finally, an incredible and vast event occurred that released an unimaginable 380 cubic miles of water from Lake Bonneville that lasted for six weeks.
Violent water flowed into the Snake River at about 48 miles per hour enlarging the Snake River Gorge 6 - 7 times its original size. Today at the Twin Falls Perrine Bridge, the canyon is about 480 feet deep. During the flood, the water level would have been 20 feet above the bridge. This catastrophic flood left Idaho with the Snake River Canyon as we see it today. 

Bonneville Lake dried up some 14,000 years ago after another major climatic change. Should it fill again, it would be as large as Lake Michigan and Salt Lake City would be 1,000 feet under water.