The Grand Canyon is so big due to millions of years of geologic processes. However, the primary reason is the erosive power of the Colorado River. Hydraulic action is a process where the flowing water from the river wore away the rock wall over time. Another factor that contributed to the growth of the Grand Canyon was freeze-thaw weathering. This is when water gets in the cracks of the rocks, freezes and expands causing the rock to break apart. These factors along with downcutting, erosion, and wind helped with gradual widening and deepening the Grand Canyon.

Angels Window is found in the Kaibab Limestone layer of the Grand Canyon. Though this layer of rock is thick and known for its resistence to erosion, overtime wind, water, and ice gradually wore away the various layers. This gives us the natural arch shaped opening, that can be viewed from the North Rim of the park. 

This is another feature located in the Kaibab Limestone Layer. Poinit Sublime has beautiful scenery with views of evergreens, wildflowers, and meadows. However, the scenery isn't the only impressive part. Similar to other creations in the park water and wind erosion shape this incredible landmark.