Glendale exists as a separate city from Denver because a long time ago, Denver leaders refused to provide water service to that area. But instead of withering away as expected, Glendale got its own water supply and thrived by providing a home for businesses that found it easier to locate there than contend with Denver zoning. The tiny municipality has always had a touchy relationship with its larger neighbor, but that could change as Glendale considers merging its fire department into Denver's. That's a big change for a town that has shared little with Denver except a congressional representative for a long time, and it is just another example of local governments in the metro area discovering the benefits of cooperation.