The crisis has turned natural gas exports into a contentious issue in Washington.
Conservative donor Charles Koch told Gates the "U.S. alone can't solve the problem."
"The math doesn't add up," 27 House Democrats said in a letter to John Kerry.
The number of railcars carrying crude oil surged 83 percent in 2013.
Sen. Mary Landrieu (D-La.) used a Senate hearing to press Kerry on the oil sands project.
Obama noted it had been five years since Congress last made a wilderness designation.
A fight over access to water for ski resorts on public land spilled into the House today, and prompted passage of a bill to protect all private water rights from being taken by the federal government.
The EPA lifted its suspension on the oil giant from receiving federal contracts Thursday.
The senator doesn't want oil refined in the Gulf of Mexico going overseas.
Sen. Mary Landrieu (D-La.) used a Senate hearing to plug the oil sands project.