"Getting Brad signed was one of our top priorities this season," team president John Davidson said. "We are counting on him to be an integral part of our offense for years to come."
Boyes, 25, is second on the team with 47 points and second in the NHL with a 20.1 shooting percentage. He's struggled along with the rest of a punchless offense in recent games, getting three goals in the last 17 games.
"I was definitely contributing earlier in the season," said Boyes, in his second season with St. Louis. "Now it's obviously a bit of a slide, and we're all not contributing the way we want. I'm here to score goals and I've got to score goals. Guys are blocking shots, guys are making saves. I've got to score goals."
The front office prefers to look at the big picture with Boyes, whose quick hands around the net and knack for finding open space have been key assets. Davidson said Boyes, one of the few offensive threats, might be putting too much pressure on himself to produce.
"We've watched him closely and we feel on many nights when he's not scoring he's the guy that gets the majority of our scoring chances," Davidson said. "If he didn't get chances, that's a whole different issue."
The Blues have totaled four goals during an 0-5-1 slump that has them on the verge of dropping out of the playoff race. Boyes, who has six winning goals, had two shots against the Sharks.
"A lot of his goals are key goals," Davidson said. "You look at our club in recent times and we're clawing and scratching to try to score a goal."
He scored 26 goals in 2005-06 for Boston, but became expendable when he totaled only 17 goals last season, the last four in 19 games with the Blues.
In 230 career games, he has 75 goals and 87 assists for 162 points, along with 75 penalty minutes.