On its beta website the U.S. Energy Information Administration (EIA) provides an overview of Canadian energy imports into the United States. The entry reveals that Canada is the "largest source of U.S. crude oil and refined products" and is "one of the few countries from which U.S. crude oil imports are increasing." Although the Keystone pipeline did not receive a presidential permit, crude oil from Alberta is being shipped by rail to points in the United States. Of interest to Houston is the Gulf Coast Pipeline Project, which began operating by rail in January 2014 from Cushing, Oklahoma to the Gulf Coast Texas refining sector with plans to expand capacity from the initial 520,000 b/d to 700,000 b/d. To see proposed routes for the actual pipelines especially for the Houston Lateral which would go through Liberty, Chambers and Harris counties, see TransCanada's map.
The EIA website entry also touches on coal, natural gas and electricity exports from Canada.