It will be near impossible for the last week or two to hook into that many in the Vedder. Before you are into fish #3, crowd will swarm your spot already.
It is possible in March in upper river targeting the wild fish which gather in upper pools/runs. But I let them spawn as many may have been hooked multiple times before they get up there.
It is possible in some hot systems in the past. My best was 25 Gold River wild beauties fishing with a buddy. We hit the canyon pools when the river was in flood. We nailed these strong fish with a spin & glow bottom boucing with 3 ft leader and just nailed the steelies non-stop. It was a turkey shoot. A day I would never forget but wouldn't want to repeat. As some one said, it is not the steelhead fishing, the walking and hunting game we are used to. So I never went back. Now the Gold is no longer golden like before.
Best day in the Vedder was 7 fish twice. One was at the bottom section of Alison near the clay hill, and another was at the Wilson Road at the tall cedars. But these were years ago. I have seen many multiple hook ups in a run in 20 years of steelheading. A school of steelie left a lower unaccessible pool to swim up to the tail out of a popular run and you will see a major steelie battle scene - easily 9 to 10 steelhead have been taken in a hurry. One year, many years ago around a Bergman bottle neck run, I heard of 50 steelies taken in one morning. People told me the day after when I was in the run. The place was full of fishermen/women, prompting me asking why so many people in one run and one guy told me the 50 fish story.
In recent years, there were some good fishing in the lower Canal section in March/April when the low river condition just trapped the steelies there. If you are lucky, you could be into a few steelies before some one discover the actions and join in to dilute your catch. But if you are by yourself and there are a dozen + new steelies just move in, you will have your day to remember.