We planned a three day hike over the long Mid-Autumn Festival 中秋節 weekend up Danda Forest Road 丹大林道 at the end of route 16 in Xinyi township 信義鄉 of Nantou county 南投縣 which just became legally accessible with permits. We ambitiously aimed to make it up and back to Rainbow lake 七彩湖 (seven-color lake) on the top of the spine of the island's mountains. This was also an exploratory hike for a later cross-island walk starting from Wanrong 萬榮 in the east and coming down on the Danda road 丹大林道 into Nantou 南投縣.
We drive down from Taipei on the eve of the holiday to avoid traffic and to get an earlier start on our first day. We stay at a pleasant commercial camp site, 達瑪巒風味餐廳. The proprietor, Mr. Lin is knowledgeable and talkative about the trails and river status. Mr. Lin tells us that a group came over from Wanrong 萬榮 after a 10 day hike just the night before.
At Heliuping all bridges are washed out. The Gondola is repaired but only usable by Forestry people. We look for a shallow path to get across the Zhuoshui River 濁水溪 just upstream of Heliuping 合流坪 before starting up the road.
The lumber magnate Sun Hai 孫海 built a wooden bridge over the Zhuoshui River 濁水溪, Sun Hai Bridge 孫海喬 in 1957 to facilitate extraction of lumber from the central mountains along the then Sunhai Road 孫海林道. At the height of operations Sun Hai employed over 3,000 people and built the 80 km road from Shuili 水里 to Heliuping 合流坪 (known as Road 16 台16線 today) to connect with what is known today as Danda Forest Road 丹大林道. In 1969 Nantou County Government 南投縣政府 converted the bridge into a cement bridge and connecting to Danda Forest Road 丹大林道. This was the only route to Rainbow Lake 七彩湖. In July of 2004, typhoon Mindulle 敏督利颱風 washed away the bridge. The Executive Yuan decided not to rebuild Sun Hai Bridge. The Executive Yuan instead decided to build a suspension bridge only able to allow passage of motorcycles, to allow the Bunun people to travel to their home land, to allow travelers access to the high mountain environment and to allow Taiwan Power path to maintain the cross-island high voltage power lines. At that time the Forestry department also established the station at Sanfensuo 三分所 to control access to the area. In 2008, typhoon Sinlaku 辛樂克颱風 destroyed the suspension bridge and it was replaced with a cable gondola. When we visited in March, the gondola was out of service. Now the gondola seems repaired with new signs and locks strictly limiting its use to Forestry personnel.
At Erfensuo station 二分所 the guard checks our permits and tells us that that there is one couple ahead of us. He warns us that there have recently been reports of landslides starting 1t 16.8 k through about 23 k, but then the road should be all clear after that. He also explains that this control station was formerly at Sanfensuo 三分所, but had to be pulled back to Erfensuo 二分所 due to damage after an earthquake. The name Erfensuo station 二分所 suggests that this is the station at 2 tenths of the way along the road.
Green TaiPower signs indicate spur trails off of the main road to maintain specific power pylons, in this case pylon 54.
Sanfensuo 三分所 was the main control point for the road for many years. This station has been abandoned as cars can no longer reach it and the control point has retreated to Erfensuo, at about 4.5 k in.
The buildings were added to over the years leaving signs of layered projects and construction but today the site seems uncared for with trash and broken things inside and outside the buildings. Clearly the buildings are still used by backpackers and it is easy to imagine that it has often served as a welcome refuge.
We are out of water when we reach Qanituan, so drop our packs and hike another 2 km up the road before we find a stream to collect water
Annual average rainfall in the Zhuoshui River watershed 濁水溪流域 is 2,200 mm, which decreases moving from the mountains downstream toward the coast. 70% to 85% of the rain falls during the rainy season from May to October, and the flow of the Zhuoshui river gradually decreases from October into the dry season in winter.
The previous day we had met the couple who were on the same three-day itinerary as us to reach Rainbow lake 七彩湖 and return over three days. They confirmed the forestry guards warning that the road might be impassable at the landslides at 16.8 k. At 3 AM a small group walks through our camp of hikers with light packs but with harnesses and rope who are relieved to see our camp suggesting there are no more dangersou landslides for them to negotiate. Since we are close to the landslide, we leave are camp pitched and walk up to take a look with light packs. We get to the beginning of a section of landslides that we cannot safely cross without equipment. Back to camp, we have a quick lunch before breaking camp and starting the 15 k hike out.
A survey conducted by the Forestry bureau using trap cameras along Danda road 丹大林道 at Sanfan station 三分所 and Lieufan station 六分所 station from Nov. 2012 to Oct. 2013 recorded 2870 photos of game in 41412 hours, including 5 herbivores - sambar deer, muntjac, serow, macaque, and boar; and 4 carnivores - marten, civet, weasel, and ferret badger. Occurrence was high for sambar deer and muntjac, but low for other game. The survey was used to put forward preservation policy for the area.
A 2004 survey along Danda road 丹大林道 conducted by Taiwan Normal University 台灣師範大學生物系 recorded 38 species of mammals, including 12 protected species:
The Danda area was a traditional area of the Bunun people 布農. Two percent of Taiwan’s humans today are non-Han Pacific islanders who lived on the island before Chinese immigrants started arriving over 500 years ago. The Bunun are widely dispersed across the central mountains. In 2000, the Bunun numbered 41,038, approximately 8% of Taiwan's total indigenous population, making them the fourth-largest indigenous group.
The Danda river 丹大溪 is one of the 12 major tributaries of the Zhuoshui River 濁水溪, Taiwan’s longest river at 186 km. The headwaters of the Zhuoshui River 濁水溪 are at Hehuan mountain 合歡山 at an elevation of 3,220m. The watershed basin of the Zhuoshui River 濁水溪 has an area of 3,156.9 square kilometers. Annual average rainfall in the Zhuoshui River watershed 濁水溪流域 is 2,200 mm, which decreases moving from the mountains downstream toward the west coast. 70% to 85% of the rain falls during the rainy season from May to October, and the flow of the Zhuoshui river gradually decreases from October into the dry season in winter. The Danda river 丹大溪 quickly splits into the Danda river 丹大溪 and the Junda river 郡大溪 which each have significant tributaries all with headwaters over 3,000m.
