Home Depot’s Yellowstone National Park. Merrill Lynch’s Yosemite National Park. Exxon Mobil’s Grand Canyon National Park. You’re probably shuddering at the thought of these national treasures being linked to corporate sponsors, but thanks to new federal rule changes, this possibility is closer than you think.Since it was established, the National Park Service has thwarted attempts to commercialize these nature preserves. In the past, the parks have limited commemorations of large donations to modest, easy-to-overlook plaques. Now, during the park service’s centennial celebration, the organization is deciding to court corporate money by offering up a lot of opportunities for naming rights.