This mountain in the Cascades is called Twin Sisters--7000 ft at summit. I took the pictures from Hiway 9 just this past August except the last photo was taken by Scott Dusek also in August.
The Twin Sisters Range is an interesting outlier of the Cascade Range. Located just 21.5 miles (34.6km) from Bellingham Bay, the range sharply contrasts the rock and mountains that surround it. The rock is very red, so much so that native peoples called the range "Kwik-Kwek Smanik" believed to mean "red rock" or "red mountains". The color is related to iron content.
The range is of particular interest to climbers. The rock (olivine) is extremely grippy and makes for some of the best scrambling in Washington State. Given their proximity to Mt. Baker and Bellingham Bay the views from the range are spectacular. The Olympic Range, the Coast Range in B.C., the Picket Range, The Cheam Range B.C., and the North Cascades all provide eye candy for climbers.
South Twin Sister (the tallest of the range) saw its first ascent on August 1, 1891 by J.M Edson, E.A Hegg, and P.J Parris
The Twin Sister Range is the largest body of exposed Olivine (Magnesium Iron Silicate) in the Western Hemisphere. A fragment of the Subcontinental Mantle brought up by the Shuksan Thrust, the range was emplaced by faulting into sedimentary rocks of the Chuckanut Formation as a solid mass.
The few significant glaciers are retreating at a rapid rate and will probably be gone within a decade. The largest glacier is the Sisters Glacier about 1km accross. Two smaller glaciers, called the Green Glaciers, flow into Green Creek.

