Merced (Calif.) defensive end Nathan Mayfield, one of the top pass rushers in the Golden State, added two offers last week, one each from the Pac-10 and Big 12.
"Colorado offered Nathan on Thursday," said Merced head coach Rob Scheidt. "Friday, Washington State offered Nathan."
The Buffs and Cougs join Arizona and California in offering the 6-4, 215-pounder.
As a junior, Mayfield earned all-area honors after recording 53 tackles and 8.5 sacks.