Sandy does have a historic run of wild Summers, albeit very small. I've only caught three in the 12 years I fished that stretch.
Mark Bachman has done exhaustive research on this but I think the closure was more in line with keeping hatchery Summers out of the late Winter wild run spawning areas since they spawn about the same time.
When Marmot is removed I guess there will be NO MORE Summers released in the Sandy period. Part of the phasing out is releasing smolts from Cedar Cr. downstream, I think they dump some at Dodge too.
Too bad, the crowds at Cedar Cr. have kept me away this year.
IMO there is plenty of room for the wild fish and the hatchery Summers. By the end of Fall anglers have picked off a huge number of hatchery fish in the upper reaches and it is a fact that not all the natives spawn in the upper river. I can find a half dozen spots where wild fish spawn only in Oxbow Park.