Ground Stone and Cobble Tools are sometimes casual stones and sometimes well shaped tools
used for grinding, pounding, chopping, cooking, and abrading.
Cobble Tools

Cobble tools are stones and pebbles that are casually used for various purposes such as hammer
stones, chopping stones, abrading stones, anvils, heating stones for basketry cooking or
underground baking, etc.  As with cores and flake tools, cobble tools were not readily recognized
by Tribal monitors and few were plotted during the monitoring process.  It is likely that many
more cobble tools existed.

Six cobble hammer stones were recovered during the monitoring process (5 basalt and 1
sandstone).   Shapes included cigar-shaped (0-9) globular shaped (0-94), and spatula shaped
(0-379).  The cigar-shaped stone had evidence of battering on the end and the globular stone had
battering around the circumference.
Site maintained as a public service by Archaeological Research, PO Box 1353, Lucerne, CA 95458.
Contact: dr.john@wolfcreekarcheology.com
Elem Ground Stone
History and Prehistory of Lake County
and Beyond
Ground Stone

Shaped Manos (4)

Four shaped manos (3 sandstone and 1 basalt) were recovered (0-159, 386, and 387).

Cobble (unshaped) Manos (1)

One sandstone cobble mano (unshaped) was recovered (0-358).

Pestle, Flat-end (3)

Two basalt (0-97, 378) and one sandstone flat-end pestles were recovered.  One was dislodged
by a road grader after mine waste had already been removed from the area (0-191).
Bowl Mortar (1)

One sandstone mortar (0-389) was hit and broken by
road grading equipment after mine waste had already
been removed from the area.

Mortar Blank (1)

A large (15cm dia) basalt sphere with a flattened end
was graded out of the ground along the water-truck
road leading to the lake (0-263).  It is possible that this
stone was a blank to be turned into a bowl mortar.  It
may have also functioned as an anvil stone.
Mano and Metate

Five manos were recovered indicating widespread use of the mano and metate across LAK-76.  
These tools are used to crack and grind hard seeds such as sage seeds, grains (grass seeds), and
pine nuts.  Although there is no way of determining the age of these tools, archaeological work
throughout California has revealed that the addition of the mano and metate to the food
processing tool kit occurred at the start of the last global warming period (~8,000 B.P.).






Mortar and Pestle

Four pestles, one bowl mortar and one possible mortar blank were recovered during the
monitoring process.  These items indicate the processing of soft nuts (such as acorn and
buckeye).  Although there is no way of determining the age of these tools, archaeological work
throughout California has discovered that the addition of the mortar and pestle to the food
processing tool kit occurred about 5,000 B.P.  In some parts of California the heavy reliance on
soft nuts gradually overcame the use of hard seeds (grains) and the use of the mano and metate
were gradually phased out.  In other areas, both technologies were used side-by-side until the
arrival of Europeans.

Both milling and pounding technologies require the harvesting of seeds and nuts that become
available in the fall (September/October).  The existence of these tools indicates that LAK-76 was
most likely inhabited during the fall months.