Ancient mummies uncovered in Central Asia were virtually inaccessible to the West until a Penn professor with a fine sense of timing and a passion for the past overcame Chinese reticence and political fears. Mummies, always a crowd-pleaser in any museum, were a crowd-pleaser in China, too, where they went on display in museums in Xinjiang Uyghur Autonomous Region beginning in 1987.
The first time Mair saw the mummies, he was "thunderstruck." The 3,000- to 4,000-year-old mummies "looked so lifelike. I had a hard time believing they were dead that long. The faces pretty much were the way they looked in life. They retained their original skin color. Quite a few were fair, with blond, light brown and reddish hair."
The mummies were recovered in the Taklamakan desert -- the second-largest desert in the world. Its arid climate, with extreme summer heat and extreme winter cold, aided by the highly saline soil in some areas, was ideal and preserved the mummies, their clothes and burial objects.
. . . The earliest group of mummies, dating from 2000 to 1000 B.C., were not simply Caucasoid. Mair believes they are the ancestors of the Tocharians, a group that spoke an Indo-European language related to Celtic languages and to Hittite, the oldest known Indo-European language, from Anatolia or modern Turkey
Perhaps not Celtic but the The Mummies of Urumchi by Elizabeth Wayland Barber decisively identifies their clothing as very similar to Celtic weaves.
There's been some recent debate over delineating what's "Celt" vs. what's "Scythian", discussed here:
Peter S. Wells, Beyond Celts, Germans, and Scythians: Archaeology and Identity in Iron Age Europe
For myself, I try to base my usage of these terms on how they were originally used by classical authors (what I'll call the linguistic definition of the Celts and Scythians), and to interpret archaeological finds (what I'll call the archaeological definition) in relation to that usage. Linguistically speaking, Herodotus introduced subsequent authors to the names "Celt" (History 2.33: "For the river Ister begins in Celtic country and the city of Pyrene cleaves Europe in two. The Celts dwell beyond the Pillars of Heracles, and they have common borders with the Cynesii, who live furthest of all people that inhabit Europe toward the west") and "Scythian" (History 1.15, etc.--see esp. the beginning of Book 4 where Herodotous discusses various ideas about Scythian origins). Since Herodotus other references to the Scythians have been found in Assyrian writings. My approach to defining the Scythians is to start with linguistic definitions based on the descriptions of Herodotus and the Assyrians, and to identify cultural characteristics and generate archaeological definitions on that basis. I take a similar approach to defining the Celts, starting from the descriptions of Herodotus, Caesar, Livy, etc. Applying this approach tends to define the Celts and Scythians as distinct groups living in distinct geographic areas during specific time periods as described by Herodotus and others.
A different approach is to define these groups by proceeding from archaeological data--so for instance, defining the Celts in terms of archaeological interpretations of finds at Halstatt and La Tene. This approach tends to define the Celts and Scythians less distinctly (cf. for example Celts and Scythians Linked by Archaeological Discoveries).
Based on the above considerations, I think it may be helpful in this type of discussion to distinguish between the Celts and Scythians as linguistically-defined groups and as archaeologically-defined groups, and when using the archaeological definition, to distinguish common ancestors/descendants of these groups from the groups themselves as defined by the archaeological sites/strata they are associated with. The term "proto-Celt" I believe blam used in one post is useful here. We might also speak of "proto-Scythians", as well as descendants of the Celts and/or Scythians--I don't know what we'd call those; I don't like "post-Celts" or "post-Scythians", but something that expresses that idea, maybe.