Unknown Pea family

unknown flower
unknown flower
unknown flower

I collected this speciman thinking that I had a hop clover but when I looked at the picture more closely after it was blown up, it clearly is not a clover flower but some sort of a member of the pea family with a pea type flower, though the flower is very small and yellow on a plant about the size of a hop clover. Any suggestions are welcome.

Found in a dry area in NW Oregon.

- - Updated 12/20/2012
- - Updated 06/14/2009