About 8 or 9 years ago I drafted a Jeopardy Biological Opinion (BO) for the U.S. Army Corps of Engineers Mud Mountain Dam located on the White River (WR). That conclusion was based on project caused mortality to White River spring Chinook. As mentioned in OncyT's post above, White River spring Chinook were deemed "essential" to recovery of ESA listed Puget Sound (PS) Chinook. This was because the WR springs are the only early timed Chinook in central and south PS.

If I'm recalling correctly, WDFW began culturing WR springs at Minter Creek because a mere 8 adult spring Chinook returned to the WR one year. This program began as an effort to prevent extinction of WR spring Chinook. Some time later, the Muckleshoot Tribe came to a settlement agreement with Puget Sound Energy (PSE) regarding PSE's project impacts to fisheries resources. That settlement resulted in PSE building the WR hatchery on the Muckleshoot reservation across the river from the PSE diversion dam adult fish collection facillity.

The Muckleshoot Tribe immediately began culturing WR spring Chinook. I"d have to look up to see when these two hatchery programs began, but the upshot is that there came to be two hatchery programs contributing to the effort to prevent extinction of WR spring Chinook. As recently as when I wrote the draft BO, it was not the least bit clear that wild, NOR (natural origin recruits) spring Chinook could sustain themselves in the WR watershed without hatchery supplementation. So I think the NMFS ESA folks made the correct call in saying that the hatchery spring Chinook are (still) essential for recovery.

I think the question has been asked, but not officially answered is whether or not the WR spring Chinook cultured at Minter continue to be "essential" for recovery given the success of the Muckleshoot Tribe's WR hatchery in maintaining the spring Chinook population. I think culturing the fish at Minter remains as a "back up" insurance plan to the WR hatchery. That makes some sense because the WR hatchery has had, since the outset, some water quality problems due to the extreme high sediment load in the WR. Ordinarily a fish culturist would not build a hatchery at a location lacking a high quality water supply. Unfortunately that was not an option in the case of the Muckleshoot - PSE settlement. So here we are: a tribal hatchery dedicated to fish recovery via mitigation that will forever be plagued with risk to its water supply. It might be a good idea to continue culturing these fish at Minter - just in case. A different question altogether is whether anglers should be allowed to fish for returning adult springs near the terminal area. I think that depends on there being a surplus abundance of the fish, which is likely related to the size of the program. I don't have any information about that. It is outside my relationship to things WR spring Chinook related.