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MNN.COM›Earth Matters› Wilderness & Resources Assignment Earth: Ironwood Forest National Monument Read more: ASSIGNMENT EARTH Protecting 129,000 acres of rugged Sonoran desert in Arizona near the Mexican border, this monument faces unique security and pollution problems arising from illegal immigration across its terrain. (Video: Assignment Earth)   CLOSE link: You might also like: Related Topics: Assignment Earth Related Videos Assignment Earth: New uranium mining in New Mexico Assignment Earth: Controlling dangerous chemicals Assignment Earth: Plans for offshore oil drilling worry native Alaskans Assignment Earth: New rules for Yellowstone bison Comments Follow this conversation Add your comment View: All (0) Add your comment Sign in with one of these accounts or just add your comment below. Log in or create an account   Login Enter your comments E-mail: Used only for emailed comments and will not be displayed with your post Follow this conversation Notify me with an email when other people comment on this article. The posting of advertisement, profanity or personal attacks is prohibited. Click here to review our Terms of Use

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