16. Clay Riddell
$3.26 billion +14% | Last year #17 | Age: 76 Calgary, Paramount Resources Ltd., Perpetual Energy Inc., Trilogy Energy Group
He currently retains more posts and titles than many people occupy during their entire lives. But Clay Riddell is gradually transferring control of his sizable empire to his adult children. Son Jim Riddell serves as president of Paramount Resources and also holds senior posts at several of its spinoffs. Meanwhile daughter Sue Riddell Rose runs Perpetual Energy. (Like him, both trained as geologists.) Clay donated $15 million this year to the Alberta Children’s Hospital—the same hospital where his wife, now deceased, worked for more than three decades.