The Denver Post The Hillyard property, pictured Wednesday, April 21, north of Silverthorne, is the site of a proposed gravel mine. Owner Peak Materials is working through the Colorado Division of Reclamation, Mining and Safety's permitting process to mine and then reclaim the site. Photo by Ashley Low City Market grocery worker Oumar Ba breathed deep in Colorado’s Blue River Valley between wilderness mountains, remembering the beauty of his native Senegal. “I love the river,” said Ba, 30. But he also sees benefits of a proposal by Peak Materials to dig a new, 54-acre gravel mine alon...