Oberholser finished 36 holes at 11-under 129. Steve Allan had a 7-under 63 Friday and is in second at 130.
Oberholser, a winner in 2006, has been troubled by wrist injuries for almost two seasons. He is competing this week for only the second time since early July.
"I'm coming out here with a fresh look and a fresh start, and getting into the tournament rhythm of things takes some time," said Oberholser. "Obviously there's two more rounds to go, but I like the position I'm sitting in."
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