“三北防护林工程”被誉为“世界生态之最”,在完成一期、二期、三期工程建设的基础上,2001年,我省三北防护林四期工程建设任务25万亩,涉及榆林、延安等八(市、区),16个县(市、区)。共完成工程造林19.27万亩, The “Three North Shelterbelt Project” is honored as “the most ecological in the world.” On the basis of completing the construction of Phase I, Phase II and Phase III projects, in 2001, the task of building the Three North Shelterbelt Project Phase IV in our province amounted to 250,000 mu, involving Yulin, Yan’an and other eight (cities, districts), 16 counties (cities, districts). A total of 192700 acres of afforestation projects completed,