Another dcm wood ID  

looks like oak, indeed
but could maybe be a yellowed ash too?

Oak.
Oak.

A shot of the other side?
If it's oak, it's quarter-sliced. If it's quarter-sliced oak, even red oak, there should be ray flake visible. I may or may not see faint evidence of this in your second image.
My gut tells me it's quartered old-growth ash.

what a lovely chair.
I'd guess oak, too.
Best,
Aunt Mark

Oak
Looks pretty old too.

tktoo, here are a couple more...
tktoo, here are a couple more. Thanks for everyone's input.

piling on
sure looks like oak to me also

Okay, okay.
Oak, aye!

possibly primavera?
withour seeing the chair up close, it looks like it could be the primavera wood, a type of light mahogany which was also used by herman miller for the basic cabinet series/line by george nelson from 1946-early 1950's.

When (if ever) was oak a stan...
When (if ever) was oak a standard option?
There's no oak in the 52 or 55 catalog.

classic herman miller
objectworship, if you have a copy or access to the book "classic herman miller" by leslie pina for schiffer books, you will find the answer to your question (and to some of the most common eames questions posted here at d.a. often). the eames chapter of the book list all the woods offered and the years the pieces were produced, which woods and finishes are considered rare or produced in very low or limited numbers.
also, if you trust wikipedia, oak is listed in the "eames lounge chair wood" research that it was offered in 1953 and mahogany from 1946-1948.

A very good book indeed.
.