Colbert stands at 8-under-par, tied with Mike McCullough and Bob Eastwood. Eastwood was a co-leader after a first-round 65. He shot 1-under-par 71 on Saturday. That was three strokes higher than McCullough's second straight 68.
Fellow 18-hole leader, Ed Dougherty, is now tied for fifth place at 6-under-par after a 1-over-par 73. Walter Hall (69) is in solo fourth place at 7-under.
Colbert was 14 strokes lower on Saturday than he was in the first round - a round that included an eight on the par-5 ninth.
Colbert's record-tying 62 included eight birdies and an eagle at the par-5 10th.
'I didn't make any 8s today,' Colbert said. 'I hit every green and every fairway. When you do that, the game seems easier.'
Last year, Hubert Green shot 62 in the final round on his way to a five-stroke victory. He's currently 15 strokes off the lead following rounds of 80-71.
Colbert, 59, is seeking his 20th career Senior triumph, and his first since the 1998 Transamerica. The winner this week will receive $225,000.
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