Maximizing the angle of open pit mine slopes while managing the risk to workers and equipment is the goal of most open pit mine operators. Often, a small increase in the pit slope angle can significantly reduce the amount of waste rock stripping that is required and can save a mining operation millions of dollars. In the example shown below, a 300 m deep circular pit with a 50 m diameter cylindrical orebody in the centre is mined using an overall pit slope angle of 45 degrees. The effect of increasing the pit slope angle in increments of 1 degree is shown in Table 1. The design of rock slopes in open pit mines involves first gaining an understanding of the pit slope geology and geotechnical. During the feasibility stage, this information will be gathered though a geotechnical data collection program that includes mapping of outcrops, diamond drilling, and laboratory testing. The orientation and frequency of geologic structure is the most important control on slope stability. | 
