In Friday's second round, Verplank shot 6-under-par 66 to make his 36-hole total 12-under 132.
Ryan Armour (64), Tag Ridings (66), and Stephen Ames (63) all share second place at 11-under 133.
Verplank, starting his round on the back nine, charged out of the gate with birdies three of his first four holes, and six of the nine overall.
He closed the round with nine straight pars.
"I I kind of lost my rhythm a little bit," Verplank said. "It kind of got windier as the day went on and it's a different direction than you normally see around here."
First-round leader J.P. Hayes (69) fell into a tie for fifth with seven others at 10-under 134.
Among those missing the cut was 2003 PGA Champion Shaun Micheel (142).