TERRACES EAST AND WEST OF KELLOGG REGION 525 



miles north of Wallace, and by the higher part of a long narrow gravel 

 deposit mapped as capping a ridge between Nine Mile and Canyon 

 creeks. A group of terrace gravel deposits along the south side of the 

 valley from Mullan east only attain an altitude of several hundred feet 

 above the river and can not be directly compared with the Kellogg 

 system, as there is too long an interval between. 



Terraces west of Kellogg Eegion 



Patches of old river gravel on the first ridge west of Government 

 Gulch represent the 600-foot-terrace horizon. A more extensive rem- 

 nant near Corrigan Gulch has been eroded into a system of gently 

 rounded ridges, consisting mainly of a moderately fine gravel, though 

 some cobble beds appear locally. There is in the topography a strong 

 suggestion of an old channel crossing several of the neighboring rock 

 ridges, and this is probably the result of erosion partially reopening an 

 old channel. ' The valley floor at the completion of the deposit was at 

 least half a mile wide. 



On the northern border of this rolling gravel country there are two 

 remnants of the 200-foot terrace. They are on a level with a sag, 500 

 yards wide, that leads from Corrigan Gulch to Pine Creek Valley. The 

 gently undulating floor of the sag is underlaid by a deposit of apparent 

 river gravel, with an occasional small boulder of granite or other igneous 

 rocks. A deposit of well rounded, moderately fine river gravel that ex- 

 tends up the slope on the south to at least 100 feet higher than the gap 

 probably represents the gravel under the 600-foot terrace. This gap is 

 in line with a narrower but otherwise similar gap between Pine Creek, 

 and Kingston. Another gravel-floored gap occurs between Kingston 

 and Cataldo. They are evidently sections of the deep old channel that 

 were filled to a depth of 500 feet and partly reexcavated since. The 

 South Fork of the Coeur d'Alene Eiver has a new course on the north of 

 the old valley from the mouth of Corrigan Creek to near Cataldo. The 

 new valley between Pine Creek and Enaville at the mouth of the Xorth 

 Fork is a narrow crooked rocky gorge separated from the old valley by 

 a quartzite ridge that may attain an elevation of 600 feet above the river. 

 The first railroad built in the region followed the old valley in prefer- 

 ence to this gorge. Between Enaville and Kingston the river occupies 

 the old valley of the Xorth Fork, but below Kingston it passes through 

 a series of gorges that are a little narrower, much deeper, and steeper 

 walled, and hence more youthful in appearance than the corresponding 

 portions of the old valley. 



