Lake Bonneville

Introduction

Looking south, from the parking lot at the mouth of Rock Canyon, you can see the distinct wave-cut terrace where the power lines are anchored. This was the highest level of Lake Bonneville, elevation 5090 feet, and was carved between 16,000 and 14,500 years ago. It was at this time that the lake breached its outlet near Red Rock Pass in southern Idaho and flooded into the Snake River valley and on into the Columbia River and the Pacific Ocean. The lake level dropped dramatically, 300 feet, in a short period of time to an elevation of 4800 feet. While at this level, sediments were shed from the Wasatch mountains and deposited along the shoreline to form deltas that were reshaped by waves into broad terraces. This level of the lake is termed the Provo level and these delta deposits are what the BYU campus in built on. It also forms the Orem bench, point of the mountain and the surface that University of Utah, Weber State University and Utah State University are built on.