The launch is scheduled for October.
"We look forward to partnering with the Trailblazers and serving sports fans in this region with the same innovative brand of comprehensive local coverage that we feature in our other markets," said Comcast SportsNet President Jon Litner.
The Trailblazers are somewhat unique in that 21 of their games last season were not aired on TV. These days, with local cable sports networks starved for content, most teams have all of their games telecast.
Golf Channel CEO and executive vice president of sports programming for Comcast Dave Manougian will oversee the new network's launch.
Comcast already operates eight regional sports networks, and is close to taking over operational control of two others: one in New England and another in the Bay Area.