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The Mountaineer 
THE THERMAL CAVES 
J. B. Fuett 
In common with nearly all our voleanie peaks, Mount Ta- 
homa has steam issuing from the crevices in the vicinity of 
the crater. This thermal region is not confined to the crevices 
bounded by the rim of the main crater, but extends outside of 
that circle and includes a small crater which lies west of the 
main one, together with additional territory to the north of 
both. Snow and ice have filled both craters nearly full. As 
the season advances this ice mass gradually settles down leav- 
ing a well defined rim ranging in height from twenty-five to 
one hundred feet. As the center is filled with ice to an un- 
known depth, no steam can force its way to the surface. The 
diameter of the large crater is about sixteen hundred feet. 
The cireumference or region of thermal caves would therefore, 
if confined to the rim alone, extend about a mile in length. 
The large crater dips down toward the east. It is far from 
being level, while the small crater dips only a few degrees 
toward the west. The rims of the two craters meet at the 
dome of Columbia’s Crest. 
On the northwest slope of the small crater the steam has 
melted all the snow off so there can be no caves formed on the 
outside of the rim for the space of a quarter of a mile. There 
are, however, some excellent ones within the rim. All around 
the rim of the large crater are found large dome-shaped caves 
where the ice is melted by the slumbering heat beneath. As 
a party approaches the large crater from the south side, these 
caves are often a source of great danger unless the party is 
warned by some experienced leader or guide. Often there is 
only a thin shell of the roof left, through which the novice ‘may 
fall to the depth below, either to get a very cold reception or 
a very warm one or perhaps both, depending on the nature of 
the cavity. When the crater rim is reached, the danger from 
caves is over so long as the party climbs over the rocks which 
form the rim. These caves do not extend far on the outside 
on the south. On the north side the heat is so intense that the 
