Photo Credit: Frank Kovalchek

Exploring the Kenai Mountains-Turnagain Arm National Heritage Area: Gilpatrick Lode Mine Evidence

F11-1HARD ROCK MINING ON THE KENAI: The Gilpatrick Lode Operation

Location:    Milepost 49, Seward Highway

Large Gravel Pit… Keep driving through pit to reach northern side.  This will provide the best visuals

Short Description:          Mountain sides are crisscrossed with former mining roads leading up to hard rock mining operations.

Required Equipment: None

Suggested Equipment: Binoculars, Trails Across Time pg 62 (map of Kenai Mining)

Safety Consideration: None

Other Info: Access into and around gravel pit is bus friendly.  Best visuals from gravel pit is on the far north side of pit. The visual clues are on the mountain sides to the west.  This is a great place for lunch; lots of room for kids to stretch their legs.

F11-2Inquiry Prompts:  What’s Going On Here?

Have students look around for something out of place (other than of course the gravel pit which is another story). On the mountainside to the west are several lines of alders zigzagging across the face. Students may have noticed this pattern on several mountainsides in the area.

These lines of alders are evidence of mining roads leading upward to hard rock operations far above. This particular operation was named the Gilpatrick and Sprague. It was in operation during the early part of the 20th century.

 

But alas . . . there’s much more.

First Question: Why a band of alder delineating the old road? Alders quickly grow in disturbed and compromised areas (the alder will be the first to grow following the recession of a glacier.) Because of this, a sudden grove of alders can suggest a historic site… such as a road.

Next Question: Why are the historic claims in 1910 in a straight north/south row? Simply, this is where the vein of quartz that is gold bearing precipitated. The gold and quartz minerals were in solution under intense high and pressure. The solution traveled through fault zones in the rock where eventually either heat or pressure (or both) diminished causes the minerals to precipitate out of solution. The mining operations followed this line of mineralization.

Perhaps another question: But these roads go so far up into the mountains— thousands of feet. Seems it would be easier to mine lower. If would be easier… if the vein was there or if it was exposed. However, because of the location of the vein and the fact that anything lower would be buried under depositional layers, the operations were established where the gold was accessible.

One last question: What about the valleys between the claims . . . what’s up with that? The gold bearing seam was once continuous. Through plate tectonics these terranes were docked here, then uplifted. Erosion (water, glaciers, earth movement) created these valleys which effectively dispersed the material (bed rock and seams of ore) into the valleys. It is this depositional material from which placer deposits are prospected. The rich ores from the Forks area originated (a long time ago) here in these seams of ore.

 

 

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