NOTE: The cache used to be
across the highway closer to the arrastra, but due to safety
reasons I relocated it at the historical marker. If you wish to see
the arrastra, use extreme caution when crossing the highway. Step
over the guardrail and take the short flight of steps down to the
rivers edge.
An arrastra is a crude but effective tool used to extract gold
from gold bearing ore - usually gold bearing quartz. An arrestra is
a grinder, and the concept is similar to a mortar and pistle.
Arrastras were first introduced into the New World by the
Spanish in the 1500's. To use the arrastra, ore was broken into
walnut-sized chunks with a sledge hammer and placed into the
circular milling area. A large drag stone, chained to a post in the
center of the milling area, was rotated by hand or mule. The drag
stones crushed the ore into a fine powder and water was added until
a thick slurry was produced. Mercury (quicksilver) was then
introduced to the mixture which removed and amalgamated any gold
found in the ore. Several arrastras were used in the Blewett area,
but this one is the most accessable.
The following safety hazards are noted: 1) Next to a hiway.
Please use caution if crossing the hiway to view the arrastra. 2)
If you go down to see the arrastra up close, a couple of the upper
steps of the wooden stairway are broken. There is a trail you can
take next to the stairway instead.