Yakou (), also known as Guanshan Pass () or Daguanshan Pass (), is a

mountain pass A mountain pass is a navigable route through a mountain range or over a ridge. Since many of the world's mountain ranges have presented formidable barriers to travel, passes have played a key role in trade, war, and both Human migration, human a ...

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...

transversing the

Central Mountain Range The Central Mountain Range is the principal mountain range on the island of Taiwan. It runs from the north of the island to the south. Due to this separation, connecting between the west and east is not very convenient. The tallest peak of th ...

within

Yushan National Park Yushan National Park () is one of the nine national parks in Taiwan and was named after the summit Yushan, the highest peak of the park.Taoyuan, Kaohsiung Taoyuan District ( Bunun: Ngani; ) is a mountain indigenous district of Kaohsiung City, Taiwan. It is the largest district in Kaohsiung City by area and the least densely populated district in Taiwan. The population is mainly the indigenous Bu ...

and

Haiduan, Taitung Haiduan Township () is a mountain indigenous township in Taitung County, Taiwan. It has an area of 880.0382 km2, with a population of 4,224 as of February 2023. The main population is the Bunun people of the Taiwanese aborigines. Admin ...

. Yakou is known its frequent

sea of clouds A sea of clouds is an overcast layer of clouds, as viewed from above, with a relatively uniform top which shows undulations of very different lengths resembling waves on the sea. A sea of fog is formed from stratus clouds or fog and does not sh ...

on the east side due to

orographic lift Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and cr ...

from the Pacific Ocean. However, due to severe road collapses following

Typhoon Morakot Typhoon Morakot, known in the Philippines as Typhoon Kiko, was the deadliest typhoon to impact Taiwan in recorded history. The eighth named storm and fourth typhoon of the 2009 Pacific typhoon season, Morakot wrought catastrophic damage in Taiwa ...

in 2009, Yakou is currently inaccessible by car. Occasionally, the character "啞" (''yǎ'') is used in place of 埡 since the latter is a rarely used character.

History

Initially, a path made by the

Bunun people The Bunun (), also historically known as the Vonum, are a Taiwanese indigenous people. They speak the Bunun language. Unlike other aboriginal peoples in Taiwan, the Bunun are widely dispersed across the island's central mountain ranges. In the ye ...

ran through Yakou. During Japan's occupation of Taiwan, the path was widened to better govern the aboriginal population in the mountains. After Japan left the island, the path was widened into the

Southern Cross-Island Highway The Southern Cross-Island Highway (), also known as Provincial Highway No. 20, links Tainan City on the west coast to Taitung City on the east coast, on the southern section of the island of Taiwan. The road is long. From west to east, the road ...

. Construction ran between 1968 and 1972, and construction workers established a campsite near Yakou; the site of the campsite became a

hostel A hostel is a form of low-cost, short-term shared sociable lodging where guests can rent a bed, usually a bunk bed in a dormitory, with shared use of a lounge and sometimes a kitchen. Rooms can be mixed or single-sex and have private or shared b ...

operated by the

China Youth Corps The China Youth Corps (; until 2000: ), often known simply as CYC (), is a youth organization in the Republic of China. The CYC was established in 1952, on the recommendation of the then president Chiang Kai-shek; its first chairperson was his s ...

. After Typhoon Morakot in 2009, multiple sections of the Southern Cross-Island Highway collapsed from the heavy rainfall. Immediately east of Yakou, a landslide buried Daguanshan Tunnel's east entrance and its adjacent parking lot and destroyed 300 m of highway. Though not as heavily affected, the hostel closed down after the typhoon. The section of the highway from Meishan to the west and Xiangyang to the east was closed to outside traffic after the typhoon and remains closed to this day. The highway is expected to reopen in 2021.

Geology

The rock around Yakou is primarily composed of a

stratum In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ei ...

composed of

argillite :''"Argillite" may also refer to Argillite, Kentucky.'' Argillite () is a fine-grained sedimentary rock composed predominantly of indurated clay particles. Argillaceous rocks are basically lithified muds and oozes. They contain variable amounts ...

, another of

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

, and a third of

slate Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. It is the finest grained foliated metamorphic rock. ...

and

phyllite Phyllite ( ) is a type of foliated metamorphic rock created from slate that is further metamorphosed so that very fine grained white mica achieves a preferred orientation.Stephen Marshak ''Essentials of Geology'', 3rd ed. It is primarily compo ...

. Due to the parallel planes of weakness present in the rocks, Yakou and the rest of the Southern Cross-Island Highway is very prone to landslides and failures even before Typhoon Morakot in 2009, and reconstruction has proven to be very difficult.

References

{{reflist Mountain passes of Taiwan Landforms of Kaohsiung Landforms of Taitung County