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Butte's Painted Ladies: A Brief Tour of Butte's West-Side Homes
Butte, Montana: Ireland's Fifth Province
Cool Water Hula by the Berkeley Pit
OXO
Basking in the Boulder Batholith
 
by George Everett
 
One of the most pleasurable aspects of living in Butte is that it is surrounded by Montana in every direction, and some of the state's wildest and most scenic parts at that.

Complex geology is to blame; it has made Butte what it was and what it is. Butte is in the heart of a huge granite formation called the Boulder Batholith that stretches from south of Helena to north of Dillon. The Batholith was shaped by magma shoved upwards by volcanic eruptions about 60 to 70 million years ago. Then, granite (quartz monzonite) was pushed to within a few miles of the surface before rapid cooling stopped it and caused cracks and fissures to occur. Into these cracks flowed mineralized solutions, most likely from the molten magma below, containing copper, gold, silver and other now precious metals.

The same geology responsible for Butte's underground mineral wealth also created the wild variety of rock croppings on the surface. Soil that once covered the Batholith has long since eroded, exposing rock croppings in bizarre shapes and sizes.

Within a half hour drive south of Butte, the Humbug Spires near Divide stand as eerie evidence of these prehistoric upheavals. Look for huge spires rising along the western edge of the Highland Mountain range easily visible from Interstate 15.

In other places, protruding rock croppings resemble the teeth of a giant in sore need of orthodontics. To the East of Butte over Homestake Pass on I-90 the Batholith results in a crazy assortment of ruddy boulders on the east side of the pass that is known locally as The Dragonback.

A couple miles north of the Pipestone Exit on I-90 on Route 222 is Spire Rock, a popular attraction for rock climbers. Nearby, marked only on topo maps is Ringing Rocks, a strange boulder pile that attracts light hearted skiiers and hikers with hammers who make real "rock" music by banging on them like a Flinstonian xylophone. There is a similar formation in a state park in Pennsylvania, too where the rocks sound exactly like the music created in the hills near Butte.

Southeast of Butte, you can drive through more of the Batholith by taking Route 2 toward Whitehall. The stretch from Thompson Park to Pipestone Pass is known as Harding Way and it is one of the best engineered
roads in Montana with cross-country skiing on marked trails and the old Milwaukee Road rail bed on the pass.

Here, look for tall trees growing between boulders. On a closer look, you'll notice that the trees are actually growing from crevices. Soil blows into the fissures (called joints) and soon seeds follow that allow huge pine trees to flourish. After wind, rain, and ice, it is yet another way that the rocks are worn down to elemental gravel and then soil.

Resilient seeds germinate and sink roots in shallow soil in the crevices and grow tall until the wind inevitably topples them. Meanwhile the boulder that nurtured the tree has split and separated forever with no trace of what drove the solid rock apart.
This site is designed and maintained by George Everett.
© 2003 by George Everett. All rights reserved.
An earlier version of ths story appeared in Montana Magazine.


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