The South Texas Environmental Education and Research (STEER) Program of the University of Texas School of Medicine-San Antonio (UTSOMSA) provides in vivo training experiences at the US-Mexico Border for medical students, residents and other health professionals in an unusual and informative setting, one that distinguishes it from other programs in the Nation. H1N1 influenza, drug-resistant tuberculosis, rabies, pesticides, and air and water pollutants do not respect borders and have the potential to affect the entire US population. Mosquitoes don’t carry green cards, as public health officials in this region sometimes say. Offered by the University of Texas Health Science Center at San Antonio at two sites along the US-Mexico Border in Texas-- Laredo and Harlingen-- STEER was the first, and is still the only, 4-week course in the Nation that teaches health professions students and professionals about these and many other crucial environmental and public health concerns. Over the past 14 years, STEER has hosted over 500 full-time students and thousands of part-time students and health professionals from more than half the states in the US. What attracts these students to STEER are the memorable learning experiences the Border offers—experiences that engage all of the senses and cannot be found in any textbook or duplicated in the classroom.