臺灣(wan)(wan)省中(zhong)央(yang)山(shan)(shan)(shan)脈北部最高(gao)峰(feng)(feng)(feng)。海(hai)拔3740米(mi)(mi)(mi)(mi)(mi)(mi)(mi)，僅(jin)次于(yu)玉(yu)山(shan)(shan)(shan)、雪(xue)山(shan)(shan)(shan)（副峰(feng)(feng)(feng)除外）及(ji)(ji)(ji)中(zhong)央(yang)山(shan)(shan)(shan)脈中(zhong)段(duan)的(de)秀姑巒山(shan)(shan)(shan)和(he)(he)馬博拉(la)斯山(shan)(shan)(shan),居全省第5位。以(yi)(yi)南(nan)湖(hu)大(da)山(shan)(shan)(shan)（主(zhu)(zhu)(zhu)峰(feng)(feng)(feng)）為(wei)核山(shan)(shan)(shan)，周(zhou)鄰(lin)(lin)約(yue)3公里半徑(jing)內，3500米(mi)(mi)(mi)(mi)(mi)(mi)(mi)以(yi)(yi)上高(gao)峰(feng)(feng)(feng)共有7座，皆以(yi)(yi)南(nan)湖(hu)為(wei)名，簡稱北山(shan)(shan)(shan)（3535米(mi)(mi)(mi)(mi)(mi)(mi)(mi)）、北峰(feng)(feng)(feng)（3580米(mi)(mi)(mi)(mi)(mi)(mi)(mi)）、東(dong)(dong)峰(feng)(feng)(feng)(3639米(mi)(mi)(mi)(mi)(mi)(mi)(mi))、東(dong)(dong)南(nan)峰(feng)(feng)(feng)（3526米(mi)(mi)(mi)(mi)(mi)(mi)(mi)）、中(zhong)南(nan)峰(feng)(feng)(feng)(3500米(mi)(mi)(mi)(mi)(mi)(mi)(mi))、南(nan)山(shan)(shan)(shan)（3516米(mi)(mi)(mi)(mi)(mi)(mi)(mi)），為(wei)西(xi)(xi)注(zhu)臺灣(wan)(wan)海(hai)峽的(de)大(da)甲(jia)溪(xi)(xi)(xi)和(he)(he)東(dong)(dong)入(ru)太平(ping)(ping)洋的(de)立(li)霧溪(xi)(xi)(xi)分(fen)水(shui)嶺。山(shan)(shan)(shan)匯(hui)諸峰(feng)(feng)(feng)皆以(yi)(yi)粘板巖為(wei)主(zhu)(zhu)(zhu)。因(yin)高(gao)度、位置和(he)(he)地(di)勢適宜，曾是更(geng)新世冰(bing)川分(fen)布區(qu)，以(yi)(yi)主(zhu)(zhu)(zhu)峰(feng)(feng)(feng)及(ji)(ji)(ji)其(qi)(qi)外圍的(de)北、東(dong)(dong)北、東(dong)(dong)3峰(feng)(feng)(feng)為(wei)主(zhu)(zhu)(zhu)，遺跡(ji)保存甚(shen)多,冰(bing)蝕地(di)形(xing)(xing)典(dian)型，有冰(bing)斗(dou)冰(bing)川及(ji)(ji)(ji)山(shan)(shan)(shan)谷冰(bing)川，前者尤多。中(zhong)央(yang)凹地(di)（亦稱南(nan)湖(hu)谷地(di)）的(de)冰(bing)斗(dou)遺跡(ji)保存最好。南(nan)湖(hu)大(da)山(shan)(shan)(shan)一帶，冬春季節因(yin)受來自太平(ping)(ping)洋通過宜蘭三角(jiao)洲平(ping)(ping)原上空(kong)深入(ru)的(de)東(dong)(dong)北風，并受大(da)陸冷氣團(tuan)東(dong)(dong)南(nan)移影(ying)響，3000米(mi)(mi)(mi)(mi)(mi)(mi)(mi)以(yi)(yi)上地(di)區(qu)常有短期積(ji)雪(xue)甚(shen)厚，由此(ci)亦可推知本區(qu)昔時(shi)冰(bing)川生(sheng)成(cheng)和(he)(he)冰(bing)蝕地(di)形(xing)(xing)發(fa)育(yu)情況。據調查研(yan)究，在(zai)南(nan)湖(hu)主(zhu)(zhu)(zhu)峰(feng)(feng)(feng)及(ji)(ji)(ji)其(qi)(qi)東(dong)(dong)北外圍，共已發(fa)現冰(bing)斗(dou)地(di)形(xing)(xing)不下12處，底高(gao)在(zai)3300米(mi)(mi)(mi)(mi)(mi)(mi)(mi)以(yi)(yi)上，尤以(yi)(yi)3500米(mi)(mi)(mi)(mi)(mi)(mi)(mi)左右為(wei)多。位于(yu)主(zhu)(zhu)(zhu)峰(feng)(feng)(feng)東(dong)(dong)北坡的(de)一處，徑(jing)長(chang)達(da)2500米(mi)(mi)(mi)(mi)(mi)(mi)(mi)，寬約(yue)1000米(mi)(mi)(mi)(mi)(mi)(mi)(mi),其(qi)(qi)西(xi)(xi)壁中(zhong)部高(gao)約(yue)1000米(mi)(mi)(mi)(mi)(mi)(mi)(mi)的(de)陡(dou)崖,角(jiao)度大(da)致60°～70°。在(zai)此(ci)西(xi)(xi)鄰(lin)(lin)，更(geng)有長(chang)達(da)4000米(mi)(mi)(mi)(mi)(mi)(mi)(mi)，寬約(yue)1500米(mi)(mi)(mi)(mi)(mi)(mi)(mi)的(de)一處。估計南(nan)湖(hu)大(da)山(shan)(shan)(shan)冰(bing)斗(dou)群形(xing)(xing)成(cheng)時(shi)，雪(xue)線高(gao)度大(da)致相當3400～3500米(mi)(mi)(mi)(mi)(mi)(mi)(mi)。發(fa)源(yuan)于(yu)南(nan)湖(hu)大(da)山(shan)(shan)(shan)西(xi)(xi)側的(de)南(nan)湖(hu)溪(xi)(xi)(xi)及(ji)(ji)(ji)與其(qi)(qi)西(xi)(xi)鄰(lin)(lin)源(yuan)于(yu)雪(xue)山(shan)(shan)(shan)東(dong)(dong)北坡的(de)七家灣(wan)(wan)溪(xi)(xi)(xi)等（均大(da)甲(jia)溪(xi)(xi)(xi)上源(yuan)），均以(yi)(yi)產一種可能為(wei)冰(bing)期殘(can)留(liu)的(de)鮭(gui)鱒魚類著名，這種陸封型魚類即與冰(bing)川時(shi)期低溫(wen)氣候有密(mi)切聯系。
斌斌有禮 
