In 1977 the Taiwan Highway Bureau planned a new Cross Island Highway, the eastern portion of which would follow the mid and upstream sections of the Lele, running from Tafen to Walami to Yuli.
民國六十六年，台灣省公路局規劃新中橫公路，其中東線將深入樂樂溪中、上遊，再由大分、瓦拉米出玉里。