Lt. Col. John Hsu, a dentist in the 804th Medical Brigade, U.S. Army Reserves, Operations Chief for Dental Services, prepares to treat a patient at an Operation Lone Star site in Pharr, Texas, July 27, 2016. Service members from the Texas State Guard worked alongside Soldiers from the 804th Medical Brigade, U.S. Army Reserves, the Texas Department of Public Safety, the Department of State Health Services, Remote Area Medical volunteers, Cameron County Department of Health and Human Services (DHHS), City of Laredo Health Department, Hidalgo County DHHS and U.S. Public Health Services during Operation Lone Star (OLS), a week long real-time, large-scale emergency preparedness exercise in La Joya, Pharr, Brownsville, Rio Grande City and Laredo, Texas, July 25-29, 2016. OLS is an annual medical disaster preparedness training exercise, uniting federal, state and local health and human service providers, that addresses the medical needs of thousands of underserved Texas residents every year. (U.S. Army National Guard photo by Sgt. 1st Class Malcolm McClendon)