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Cut and fill is used to mine the high-grade, narrow steep vein system at the Hollister Au mine in Nevada, USA. The stope width is controlled to about 3.5 ft and, in the absence of top access, backfill material is pumped from the bottom access up into the stope through a series of pipes after the ore has been slushed out in each mining cycle. The backfill material was changed from one layer of low-strength concrete and one layer of high-strength concrete cap to one layer of low-strength cellular concrete and one layer of high-strength concrete cap. The purpose of the backfill is to prevent host rock around the mined out stopes failing or caving in, and the low-strength cellular concrete provides enough confining stress to the host rock. The cellular concrete is also waterproof so that its physical properties will not change after installation, and its volume after mixing the concrete with the foam is twice as large, reducing backfilling time and lowering costs by 30%. To reduce the steel concrete pipe set up and tear down time, which is about 2 to 3 shifts in each mining cycle, the steel pipes are left in man-ways between mining cycles. Concrete pump and pumping pipe selection, backfill mixing and mechanical properties and quality control procedures are described. Addition of fly ash into the cement and foam may cut cement cost and increase the long term-backfill while eliminating environmental problems associated with fly ash disposal., Cut and fill is used to mine the high-grade, narrow steep vein system at the Hollister Au mine in Nevada, USA. The stope width is controlled to about 3.5 ft and, in the absence of top access, backfill material is pumped from the bottom access up into the stope through a series of pipes after the ore has been slushed out in each mining cycle. The backfill material was changed from one layer of low-strength concrete and one layer of high-strength concrete cap to one layer of low-strength cellular concrete and one layer of high-strength concrete cap. The purpose of the backfill is to prevent host rock around the mined out stopes failing or caving in, and the low-strength cellular concrete provides enough confining stress to the host rock. The cellular concrete is also waterproof so that its physical properties will not change after installation, and its volume after mixing the concrete with the foam is twice as large, reducing backfilling time and lowering costs by 30%. To reduce the steel concrete pipe set up and tear down time, which is about 2 to 3 shifts in each mining cycle, the steel pipes are left in man-ways between mining cycles. Concrete pump and pumping pipe selection, backfill mixing and mechanical properties and quality control procedures are described. Addition of fly ash into the cement and foam may cut cement cost and increase the long term-backfill while eliminating environmental problems associated with fly ash disposal.