Maryland Attorney General Brian Frosh has joined a coalition of 12 attorneys general in filing an amicus brief for the Ninth Circuit in support of environmental groups’ challenge to the Keystone XL Pipeline. The pipeline is an expansion to an existing pipeline system that would transport up to 830,000 barrels of crude oil per day, from Alberta, Canada to existing pipeline facilities near Steele City, Nebraska. The pipeline would also transport natural gas along parts of the Appalachian Trail.