"For decades, cowboys known as 'tick riders' have patrolled the U.S.-Mexico border to prevent cattle carrying 'fever ticks' from entering."

"OKLAHOMA CITY (AP) — High temperatures and an ongoing drought are having an impact on more than just crops and livestock. State health officials say they are also creating ideal conditions for the growth of a tiny, single-cell organism that lives in Oklahoma's rivers, lakes and ponds and can cause a disease that is almost always fatal."

"The Canadian pipeline company TransCanada has quietly begun construction of the southern leg of the controversial Keystone XL pipeline, installing segments near Livingston, Texas, company officials confirmed Thursday."

"The Arizona city already logs more days over 100 degrees than any U.S. city, and climate researchers predict Phoenix will grow hotter still in the coming decades. Planners are taking the projections seriously, and are looking for ways to adapt the city and its residents to a hotter, drier reality."

"DALLAS - Suffering from the nation's deadliest outbreak of West Nile virus this year, Dallas County authorized aerial spraying of insecticide on Friday for the first time in nearly five decades to help fight the mosquito-born illness."

"Faced with a booming population and a disappearing water supply, the city of San Antonio responded by dramatically cutting consumption, pioneering new storage techniques and investing in water recycling and desalination projects. It now boasts that it is 'Water's Most Resourceful City.'"

"FLAGSTAFF, Ariz. -- The U.S. Environmental Protection Agency has issued its final rule aimed at cleaning up the largest single source of haze-causing pollutants in the country."

"Work was scarce for architect David Mullican and many Galveston Island builders after hurricane Ike. As damages were assessed, insurance claims disputed and homes were repaired piecemeal, Mullican was out of work for more than a year."

"OKLAHOMA CITY -- Some Oklahoma residents have returned to emergency shelters despite evacuation orders in many areas of the state being lifted, as wildfires continued to burn."