By Amanda Eggert EBS Associate Editor

The Montana Fish, Wildlife and Parks Commission today reopened parts of the Yellowstone River that the agency closed on Aug. 19 due to a parasite that killed thousands of mountain whitefish.

As of Sept. 1, the upper stretch of the river and its tributaries—from the Yellowstone National Park boundary near Gardiner to the Carbella Fishing Access site—is open to non-angling recreational uses.

The main stem stretch of the Yellowstone hardest hit by the parasite—from Carbella to the Highway 89 bridge in Livingston—will remain closed to all recreational activities including fishing. The tributaries of that stretch, including spring creeks, will reopen to fishing and other recreational uses. FWP biologists will float that stretch again on Tuesday, Sept. 6. “In the event this section does not show any detrimental change in fishery health, it will be open immediately to all uses that day,” according to a press release from the agency.

The lower reach, from the Highway 89 bridge in Livingston to the Highway 212 bridge in Laurel, is open to all angling and recreational uses with the exception of the Shields River and its tributaries, which will remain closed to protect Yellowstone cutthroat trout. All other tributaries on this stretch will be reopened.

During a FWP commission conference call this afternoon, the agency’s chief legal council, Becky Dockter, noted that the language in the closure allows the agency to reinstate the closure if environmental conditions deteriorate.

“The mortality that we’ve observed seems to have slowed,” said Travis Horton, FWP’s Region 3 fisheries manager. During surveys conducted this week, the agency has not seen any actively dying fish, as they have in weeks past. “We did see a few fresh-looking fish, but we’re not sure when they died.”

Horton also noted that water temperatures have eased some. The peak temperature Aug. 31 was approximately 64 F, he said, whereas it had previously been closer to 68-70 F.

FWP conducted weekly surveys starting the second week of August. During their third week of surveys, they counted 1,700 dead fish in the hardest-hit area—Grey Owl Fishing Access 3 miles north of Emigrant to Loch Leven Fishing Access 9 miles south of Livingston.

The agency counted 900 dead fish during the most recent survey of that stretch. Apart from saving some samples for lab analysis, FWP did not collect the fish counted. Horton said the lower number from the most recent survey likely reflects the efforts of people who’ve been picking them up or consumption by scavengers.

Horton said the impacts of the parasite were far greater on whitefish, but FWP biologists did count 20-50 dead trout as well. He recommended that the agency continue to solicit reports from the public based on what they’re seeing on the Yellowstone and its tributaries.

The morning of Aug. 29, Gov. Steve Bullock declared a state of emergency due to aquatic invasive species in response to the closure, which had swift and significant impacts on the area’s economy.

Dan Vermillion, commissioner for the southwest region of FWP, expressed appreciation for the public, outfitters and guides who “put the resource first” and considered the long-term health of the river.

“It [did] indeed have a pretty significant impact on a lot of folks,” Vermillion said. “That’s why the governor pushed on us to make sure that we were focused on this and putting this river back into the open column as soon as possible.”

The FWP press release also noted that as part of the re-opening of the Yellowstone, the agency is placing two aquatic invasive species inspection stations on the I-90 corridor near Livingston and Hardin. According to the release, “All watercraft must stop at AIS inspection stations. This includes rafts, float tubes, kayaks and stand up paddle boards, along with motorized watercraft”

The agency continues to urge the public to clean, drain and dry their boats and fishing gear to limit the spread of aquatic invasive species.

“Anybody who plans to go out fishing tomorrow—I hope the first stop they make is to the car wash and get those boats cleaned off,” Vermillion said. “If we want these rivers to remain open, we all need to do our part.”