BILLINGS, Mont. (AP) – A Canadian company that wants to build a massive pipeline linking Alberta’s oil sands to U.S. refineries says it would include safety measures to prevent a spill like the one that fouled the Yellowstone River last month. TransCanada executives visiting Montana on Tuesday offered that pledge to shore up support for its $7 billion project assailed by environmentalists as too risky. The U.S. State Department plans to release its final analysis of the Keystone XL pipeline this month. Opponents say approval could lead to more spills like the Exxon Mobil pipeline rupture in July that spewed an estimated 1,000 barrels of oil into the Yellowstone.  TransCanada president Alex Pourbaix says the line would be buried at least 25 feet beneath major river crossings to lower the risk of spills.