This is the cropped panorama of Yumthang Valley on your East across the river intersecting the valley North-South. The iron rich earth is very evident in the mountains of Yumthang which you will be seeing right in front of you. The altitude is approximately 12,000 feet ASL; though few may sense lack of oxygen at this elevation many would be completely enthralled.
I have added large version as per Goldy's suggestion.
The thumb-shaped state of Sikkim is characterised by wholly mountainous terrain. Almost the entire state is hilly, with the elevation ranging from 280 metres (920 ft) to 8,585 metres (28,000 ft). The summit of the Kangchenjunga is the highest point which falls in Nepal among the top 8 mountains residing on Nepal. For the most part, the land is unfit for agriculture because of the precipitous and rocky slopes. However, certain hill slopes have been converted into farm lands using terrace farming techniques. Numerous snow-fed streams in Sikkim have carved out river valleys in the west and south of the state. These streams combine into the Teesta and its tributary, the Rangeet. The Teesta, described as the "lifeline of Sikkim", flows through the state from north to south. About a third of the land is heavily forested.
The hills of Sikkim mainly consist of gneissose and half-schistose rocks, making their soil brown clay, and generally poor and shallow. The soil is coarse, with large amounts of iron oxide concentrations, ranging from neutral to acidic and has poor organic and mineral nutrients. This type of soil tends to support evergreen and deciduous forests.
A large portion of the Sikkim territory is covered by the Precambrian rock and is much younger in age than the hills. The rock consists of phyllites and schists and therefore the slopes are highly susceptible to weathering and prone to erosion. This, combined with the intense rain, causes extensive soil erosion and heavy loss of soil nutrients through leaching. As a result, landslides are frequent, isolating the numerous small towns and villages from the major urban centres.
Source:^ a b c d e f "Physical Features of Sikkim". Department of Information and Public Relations, Government of Sikkim. 2005-09-29.