In a few areas, people traveling through areas of old placer tailings, expecting the area to be some sort of wasteland, are pleased to find a great variety of fishing and water sport recreation available, and thriving wildlife in the habitat that has been created. Because large placer deposits can be thoroughly explored before floating the dredge, such operations lend themselves to thorough planning, and it is possible to do a considerable amount of reclamation at only slight increase in overall operating costs. Actually this kind of operation is uncommon, as it involves a mine opening at the surface, from which ore is removed by gravity through raises connected to adit haulageways beneath, and by tramming the ore to the surface on the haulage level. The glory hole method is best suited to mining on a hillside, and irregular deposits can be cleanly mined without dilution by waste wall rock. The benches are mined away as work descends to the bottom of the deposit or to the haulageway, so that spectacular steep sidewalls may result if the walls do not slough in.
Mining can be quite selective, and little waste rock is thrown on the surface dumps.
The principal environmental objection to the method is difficulty in reclamation of the surface of the mine area. In one mine, it may be desirable to plan for blending variations in the ore so as to maintain, as nearly as possible, a uniform feed to the mill. The grade and tonnage of material available will determine how much waste rock can be stripped, and there is often an ultimate limit to the pit that is determined more by the economics of removing overburden than a sudden change in the ore deposit from mineral to nonmineral bearing material. The ultimate pit limit and the slope of the pit walls are therefore determined as much by economics and engineering as by geological structure. Material that is relatively high grade may be left unmined in some awkward spot extending back too deeply beneath waste.