Chris Couch, who held a share of the lead after each of the first two rounds, shares second place with Bubba Watson. That pair stands at 11-under-par 205, one stroke clear of Jason Dufner, Ryuji Imada and Mark Wurtz.
Bohn got off to a slow start at Shadow Hills Country Club as he opened with four straight pars. He then birdied the par-5 fifth to move to minus-11. After another string of pars, Bohn capped the front side with a birdie at the par-5 ninth.
Around the turn, Bohn found trouble. He bogeyed the 10th and again dropped a shot at the 12th. That left him at 10-under for the tournament.
Bohn, who once shot a 58 in the 2001 Bayer Championship on the Canadian Tour, came back with a birdie at the par-4 14th to grab a share of the lead.
With five other players within one stroke of the lead, Bohn moved ahead of the pack with an eagle at the 18th. He missed the green at the par-5 closing hole, but was able to sink his 40-yard chip.
'It is just kind of pot luck,' said Bohn. 'I was just trying to get on the green, about 15 feet away from the hole and have a birdie chance. I've had some luck in my day and this will go right up there with it.'
Couch jumped out in front early, but fell back to the field. He ran off back- to-back birdies from the first to move to 12-under. He climbed to minus-13 with a birdie at the par-5 fifth.
However, things started to come undone from there. Couch bogeyed the sixth, but responded with a birdie at the next. He again dropped a shot at No. 9.
He answered that mistake, however with a birdie at the 10th, but that would be his last birdie of the day. Couch later faltered to consecutive bogeys from the 13th that dropped him to minus-11. He could only manage four pars on his way to the clubhouse.
'The chip-in by Jason on No. 18 was a big shot,' Couch said. 'That is how you win golf tournaments. But I'm in good position. I just want to have some fun in the final round.'
Watson opened the day three strokes off the lead. He cut into that deficit quickly, though, as he holed out for eagle on the par-4 second. He later sank back-to-back birdies from the seventh to move to 11-under.
However, he bogeyed two of the next three holes to fall back off the pace. He was able to climb back into the hunt with two straight birdies from the 13th.
'My goal was to shoot in the 60s every round this week,' said Watson, who carded his second straight 4-under 68. 'The eagle on the second hole kind of helped the day right there. I might be nervous as heck Sunday. But I'll be excited nervous, not scared nervous. My goal is to shoot 68 because I feel I should reach all the par-5s.'
Emlyn Aubrey and Ted Purdy share seventh place at 8-under-par 208. Andrew McLardy fired a 5-under 67 to move into a share of ninth place. He is joined at 7-under-par 209 by Jaxon Brigman, Terry Hatch, Ryan Howison and Bo Van Pelt.