Carrie Tolstedt

With 6,200 branches, 105,000 employees, and 12,500 ATMs under her control, Tolstedt runs the country's biggest retail bank network. (Wells Fargo estimates that in the 39 states in which it operates, half of all households are within two miles of a branch or an ATM.) To boost efficiency and cut down on real estate costs, last year Tolstedt introduced a virtually paperless, pared-down 1,000-square-foot storefront. She also stepped up small-business lending, issuing a record $18.9 billion in new loan commitments in 2013, as well as issuing more money in Small Business Administration-backed loans than any other bank by a factor of two.