If the group's work is suspended until then and isn't able to give input, it’s unclear what the Bureau of Reclamation will decide to do on the budget, Stevens said.

Hamill guessed that federal agencies will be left to use other means to get input then to make “whatever decision they want,” based on that.

“There was a lot of thought put into creating the Adaptive Management Work Group to get input on a complex program. I don't know what the plan B is,” Hamill said. “Everybody is kind of puzzled about it.”

Also halted is work on a plan to address brown trout in the Lees Ferry reach of the Colorado River that Hamill said have increased substantially in number over the past three to four years. The fish are especially concerning because they are voracious eaters and can feed on small fish, Hamill said.

In February, the group decided to organize a workshop examining the reasons for an increase in brown trout, the risks the fish pose to rainbow trout and other native fish and the influence of high flow releases from Glen Canyon Dam on the fish populations.

“That whole thing has been put on hold, too,” Hamill said.