本書作者從空中攝影及田野訪查記錄中，在飛閱「臺三線」的自然、人文與地景的同時，也能窺探先民當年面對族群關係緊張時期的艱辛。以歷史的角度，從台中東勢到桃園龍潭這段「臺三線」，就是土牛紅線（土牛溝）、隘勇線、古道運輸線。臺三線沿線地區，產業是多元的，需要複雜的技術，也結合大型的商業行為；相對於平原地區，傳統都以稻米為主，較為安定。印證了在平原安全無虞，但只能種稻，山裡頭未臻之地雖然佈滿危險，但是也充滿著機會的寶庫。
英文內容大要：Fromthedirector’saerialdocumentaryfilmandfieldsurveyrecords,thefilmingof“TaiwanRoute3“didnotonlyshowthatofTaiwan’snature,humanitiesandlandscapes,butalsogaveaglimpseofthehardshipswhentheearlysettlersencounteredgreatethnictensionsatthetime.Fromahistoricalperspective,the“TaiwanRoute3“extendsfromtheTaichungDongshitotheTaoyuanLongtanistheaboriginalboundary(Tu-niuDitch),theDefenselineoffrontiergourdboundaryandtheancientroutetransportationline.IntheareasalongtheTaiwanRoute3,theindustryisdiversified,requiringcomplextechnologiesandintegratinglarge-scalecommercialactivities.Comparedwiththeareasintheplains,thetraditionalindustryisdominatedbyricecultivation.Itprovesthatitissafeandsoundtogrowintheplains,butonlytogrowrice.Althoughtheunfinishedlandinthemountainsisfullofdanger,itisalsofulloftreasures.
