Tribes have long struggled to develop their economies, so when mining companies promised jobs and a revenue stream decades ago, many American Indian tribes jumped at the chance to work in the mines, particularly on the Navajo Nation and around Grants, N.M. Thus far, mining companies have been hard-pressed to convince tribes that the health risks and environmental degradation they associate with past uranium mining would not occur with new mining operations, said David Brett, president and chief executive of Pacific Bay Minerals Ltd. The Vancouver, Canada, company had been in negotiations to explore for uranium on the Hualapai reservation, where tribal leaders renewed a ban this month. "There is a perception out there that is very hard to dislodge that it poses this massive health risk," he said. While it wasn't known how much uranium could be mined from the nearly 1 million-acre Hualapai reservation, Brett said previous work had shown there was potential. "This is what made it so attractive; it's basically unexplored territory," he said. "It's geologically crying out to be explored." The frustration is just as evident on the nearly 1 million-acre area around the Grand Canyon that the Interior Department in July blocked from any new mining claims for a two-year period.