1853
question: In what year did gold extraction turn to more difficult locations?, context: By 1853, most of the easily accessible gold had been collected, and attention turned to extracting gold from more difficult locations. Hydraulic mining was used on ancient gold-bearing gravel beds on hillsides and bluffs in the gold fields.:89 In hydraulic mining, a high-pressure hose directed a powerful stream or jet of water at gold-bearing gravel beds. By the mid-1880s, it is estimated that 11 million ounces (340 t) of gold (worth approximately US$15 billion at December 2010 prices) had been recovered by "hydraulicking". A byproduct of these extraction methods was that large amounts of gravel, silt, heavy metals, and other pollutants went into streams and rivers.:32–36 As of 1999[update], many areas still bear the scars of hydraulic mining, since the resulting exposed earth and downstream gravel deposits do not support plant life.:116–121
In what year did gold extraction turn to more difficult locations?
By 1853 , most of the easily accessible gold had been collected, and attention turned to extracting gold from more difficult locations.
By 1853, most of the easily accessible gold had been collected, and attention turned to extracting gold from more difficult locations. Hydraulic mining was used on ancient gold-bearing gravel beds on hillsides and bluffs in the gold fields.:89 In hydraulic mining, a high-pressure hose directed a powerful stream or jet of water at gold-bearing gravel beds. By the mid-1880s, it is estimated that 11 million ounces (340 t) of gold (worth approximately US$15 billion at December 2010 prices) had been recovered by "hydraulicking". A byproduct of these extraction methods was that large amounts of gravel, silt, heavy metals, and other pollutants went into streams and rivers.:32–36 As of 1999[update], many areas still bear the scars of hydraulic mining, since the resulting exposed earth and downstream gravel deposits do not support plant life.:116–121
By <hl> 1853 <hl> , most of the easily accessible gold had been collected, and attention turned to extracting gold from more difficult locations.
By <hl> 1853 <hl>, most of the easily accessible gold had been collected, and attention turned to extracting gold from more difficult locations. Hydraulic mining was used on ancient gold-bearing gravel beds on hillsides and bluffs in the gold fields.:89 In hydraulic mining, a high-pressure hose directed a powerful stream or jet of water at gold-bearing gravel beds. By the mid-1880s, it is estimated that 11 million ounces (340 t) of gold (worth approximately US$15 billion at December 2010 prices) had been recovered by "hydraulicking". A byproduct of these extraction methods was that large amounts of gravel, silt, heavy metals, and other pollutants went into streams and rivers.:32–36 As of 1999[update], many areas still bear the scars of hydraulic mining, since the resulting exposed earth and downstream gravel deposits do not support plant life.:116–121
<hl> By 1853 , most of the easily accessible gold had been collected, and attention turned to extracting gold from more difficult locations. <hl> Hydraulic mining was used on ancient gold-bearing gravel beds on hillsides and bluffs in the gold fields.:89 In hydraulic mining, a high-pressure hose directed a powerful stream or jet of water at gold-bearing gravel beds. By the mid-1880s, it is estimated that 11 million ounces (340 t) of gold (worth approximately US$15 billion at December 2010 prices) had been recovered by "hydraulicking". A byproduct of these extraction methods was that large amounts of gravel, silt, heavy metals, and other pollutants went into streams and rivers.:32–36 As of 1999[update], many areas still bear the scars of hydraulic mining, since the resulting exposed earth and downstream gravel deposits do not support plant life.:116–121