Calcavecchia played his last seven holes in five-under par to shoot a five- under 67 on Saturday. Perry's four-under 68 included an eagle, two birdies, a double-bogey and a bogey in his final six holes.
Sluman shot a two-under 70, while Cochran managed a one-under 71 to join the logjam at seven-under 137.
The quartet is two strokes clear at the TPC Snoqualmie Ridge.
Chien Soon Lu, Bob Gilder and Chip Beck each posted rounds of three-under 69 on Saturday and are knotted at minus-five.
Nick Price also carded a three-under 69 and is alone in eighth at four-under 140.
Last week's Senior Players Champion and local favorite Fred Couples shot a three-under 69 and moved up into a tie for 13th at two-under par.
MORE TO FOLLOW.