This group of mountains was briefly covered in the book on page 347. Old maps identified these mountains as both the Goose Creek Mountains and the Cassia Mountains. The later two names have disappeared from use and this area is now simply known as the South Hills. Recognizing both local usage and the absence of the old names from newer maps, the older names are hereby abandoned.
The name South Hills is somewhat misleading because this uplift is undoubtedly a group of mountains. These mountains stretch roughly 25 miles from north to south and 20 miles east to west, forming a group of complicated ridges and peaks; 8,050-foot Monument Peak is the highest summit. One of the most prominent features of the Goose Creek Mountains is a long north/south ridge line known as Deadline Ridge, which runs from Grand View Peak south into Nevada. The range has a sedimentary foundation covered by thick deposits of rhyolite. In addition to Monument Peak the range has many other named and unnamed summits.
The range has many deep canyons with Rock Creek Canyon the most outstanding example. There are extensive stands of fir forests and aspen groves interpseresed with meadows and flower covered ridges throughout the range.
“This was the TOUGHEST climb I did in the South Hills. It completely changed my opinion of how easy/difficult the South Hills would be. The patches of forest (and/or willows/brush) in the South Hills can be IMPENETRABLE and are a dangerous situation. No kidding. I opted for the easiest routes I could muster up from here on out. That’s how much this climb affected me. You can’t just do ridge traverses here and expect to be able to complete them. You can get absolutely shut down by the thick terrain, even in seemingly short patches (if you can’t go around them).”
These mountains have an extensive road system which is maintained by the Forest Service. Primary access is from the north via the paved Rock Creek Road which leads to the Magic Mountain Ski Area. Beyond the ski area improved roads lead to Deadline Ridge and also to Oakley, Idaho. In addition to the improved roads many other dirt roads lead to or near many of the area peaks. Improved FS-507 leads to the summit of Pike Mountain. Finally, this range is used a lot of use by ATVs and dirt bikes and there are many trails catering to these visitors.
The unimproved roads and ATV trails are a good substitute for hiking trails and can be used for long ridge walks as well accessing peaks. Visitation in early summer is high along the main corridor past the ski area but this is big country and you can find solitude if you look for it.