The Great Plains Shelterbelt was a project to create windbreaks in the Great Plains states of the United States, that began in 1934. President Franklin D. Roosevelt initiated the project in response to the severe dust storms of the Dust Bowl, which resulted in significant soil erosion and drought. The United States Forest Service believed that planting trees on the perimeters of farms would reduce wind velocity and lessen evaporation of moisture from the soil. By 1942, 220 million trees had been planted, stretching out 18,600 miles (29,900 km) in a 100-mile-wide zone from Canada to the Brazos River. Even as of 2007, "the federal response to the Dust Bowl, including the PSFP [Prairie States Forestry Program] which planted the Great Plains Shelterbelt and creation of the Soil Erosion Service