"At a beef industry conference in Denver last week, the animal health auditor for meat producer JBS USA presented a video showing short clips of cows struggling to walk and displaying other signs of distress. The animals appeared to step gingerly, as if on hot metal, and showed signs of lameness, according to four people who saw the video."

"Hyperloop plans revealed Monday envision a 'fifth mode of transport' in which passengers travel at extreme speeds through tubes to reach their destination. Elon Musk, chief executive of Tesla Motors and SpaceX, says the idea is 'extremely speculative.' But if Elon Musk's hyperloop is ever built, it could revolutionize transportation and energy."

"Two decades [after a tour of US National Parks, Audrey and Frank Peterman] ... are vocal and well-known parks advocates. One thing in particular has driven their passion: the lack of diversity in visitors to the national parks, a problem that also has long plagued the National Park Service."

"Americans can expect more major power outages because of severe weather driven by climate change, a federal report says."

"Crude oil shipped by railroad from North Dakota is drawing fresh scrutiny from regulators concerned that the cargo is adding environmental and safety hazards, something that analysts say could raise costs."

TransCanada and Department of Homeland Security keep close eye on activists, FOIA documents reveal."

A legislative and regulatory battle over slaughter of wild horses is dividing conservation celebrities and American Indians in the Southwest and Mountain West.

"As fans of 'Duck Dynasty' can attest, hunting for nutria – big, water-loving rodents with bright orange front teeth – is hugely popular in Louisiana. This might not be exclusive to the bayou for long. As winters warm, nutria could migrate across the country, according to new research."

"Heat waves are the deadliest of extreme weather events, the Centers for Disease Control and Prevention reported this week."

"MARSHALL, Mich. — As the Obama administration inches closer to a decision on whether to approve construction of the much-debated Keystone XL pipeline, costly cleanup efforts in two communities stricken by oil spills portend the potential hazards of transporting heavy Canadian crude."