Rumbling, shaking, rattling, voracious,
huge portable mining dredges of yesteryear played rhythmic tattoos, heard
for miles in all directions!! 24 hours a day, 7 days a week, 363 days a
year, they only closed down for July 4th, and Christmas. Now THAT
is gold fever!
|Ravenously and unsatiably famished for
virgin gravels, these behemoths gobbled a quarter of a million cubic yards
of material per month without stopping. Every Wednesday, the bucketline
would be slowed so that workers could scramble out on the boom and replace
the cast iron "lips" --one per scoop. Then the pitch of the incessant
drone of huge electrically fed engines would rev up higher and higher informing
the valley "the lips were in and the hunt was on!" Again!
||Just a handful are still visible.
Most of these giant dredges are nothing more than rotting foundations submerged
in final resting place ponds. Over 100 of these huge dredges were
in operation in the western USA and Canada at the turn of the previous
century. Sometimes, all that remains are "tombstones" on current
area road maps, such as the Pomeroy Walking Dredge label on roadmaps of
eastern Oregon on Interstate 84, at Waverly. All the remains of the
Pomeroy is the gigantic toothy gear which turned the Pomeroy first this
way, then that way as the boom operator searched for the yellow metal from
his perch 10' off the ground.
|The Sumpter Dredge has found
a new lease on life, setting it apart from others decomposing in their
watery graves. Instead of permitting it to be raided for parts and
shipped elsewhere, retired operations crew show here hatched a plan in
1994 to restore the Sumpter Dredge, and are making remarkable progress.
Already, people can walk onto and through the dredge from May to September
each year, currently at no cost.
Valley gravels in the path of
the always hungry Sumpter Dredge encompassed approximately 2500 acres and
were 18' to 20' deep. The bedrock was characterized as soft decomposed
rock the early dredgers called "clay webfoot." It snaked through
this area as can be observed in aerial photographs. Creating it's
own 8-10 foot pond barely wider than its hull as it went, the water usages
were minimal compared to the gravels consumed. If one examines the
stacker end view of the dredge, one will see what appears to be a gigantic
Iron "H" configuration with a "3rd leg" inside the "H." That is the
gigantic anchor staub that was winched up to allow the dredge to float
sideways 6' to 9' feet, to the edge of its then existing pond. Then
the 3rd leg was allowed to free fall into the bedrock, stabilizing the
dredge so that the bucketline could continue scooping and dumping, scooping
and dumping, scooping and dumping, 25 buckets per minute.
This bottomland, easily scooped
up by the buckets, dumped their payloads into a gigantic internal trommel
with 3/4" welded screen openings. Then internal sluices concentrated
the ore even more, before it was manually screened by the crew chief.
Therein would be found hundreds and thousands of small pieces of iron,
and iron shot from the prior century's American Indian battles and hunting
parties in the valley. That magnetic junk all had to be manually
sieved out and removed before the foreman would turn over the concentrates
to a group of expert panners. The final panning took place upstairs,
in locked offices above, on the bucketline end of the dredge. There
are pictures in the museum archives which bear mute testimony to the amount
of iron junk that had to be dealt with to get at the gold.
From October 1942 to May 1945, the War
Production Board prohibited gold mining in the USA. THAT silenced
Sumpter #3. After the WWII was won by the Allies, Sumpter #3's ancient
sluices were replaced with $75,000 worth of jigs, naturally vibrating due
to the incessant and constantly jarring off-loading of the 9 cubic foot
buckets. All 72 of them. Many think, due to the small size
of the gold encountered throughout Sumpter Valley's dredging history, this
modernization permitted the grinding, belching, diesel soaked interior
to still seine out the gold until 1954 when many other gold giants in North
America had long since been silenced by their owners.
||What is most astounding is the fact that
most of the gold captured from this clay webfoot bedrock was only minus
8 mesh gold or smaller!!! For those unfamiliar with how small that
is, look at any "0" in a number in this article, and you'll see size "minus
8" gold size. Hardly any sizeable nuggets were found in all the years
of Sumpter #1, #2 or #3's operations. Sumpter #3 is 125' long from stacker
tip to bucketline boom extension. It was originally constructed for $350,000
in 1935 dollars, when gold was $35 an ounce. It recovered over $4.5
million dollars in $35 an ounce gold, an astounding feat when considering
the small gold sizes recovered and the amount of manual hand panning done
to apprehend the golden results!
by Megan Rose
Author: Thrift Store Prospecting
Copyright Pen Press, PO BOX 321, PARMA ID 83660-0321, Office: 208-722-7722
One-time use and archival permission granted to Nick Laird.