“The Trinity River is the biggest problem you have in Dallas today,” declared landscape architect George Kessler in his comprehensive plan for the city a century ago. And so it has remained: an undeveloped flood-prone eyesore that requires an extensive system of levees to protect residents and property. On March 29 that legacy will be left behind with the opening of the soaring four-hundred-foot-tall Margaret Hunt Hill Bridge, which spans the river to connect downtown with West Dallas. Designed by celebrated Spanish architect Santiago Calatrava, the graceful steel-cabled structure with a single monumental arch lays claim to the kind of city Dallas hopes to become in the new century: aspirational, energetic, and engaged. And now that Dallas has its signature bridge, perhaps the issue that so vexed Kessler can finally be solved—transforming the city’s most challenging problem into its greatest asset.