The Montana Fish, Wildlife & Parks Commission agreed to closed a 19-mile stretch of the upper Big Hole River today to all angling due to extremely low water conditions that threaten the survival the river's native Arctic grayling population. The closure will take effect Saturday, July 1.
"The flows and water temperatures in the upper Big Hole River are now at levels detrimental to the river's wild grayling," said FWP Fisheries Division chief Larry Peterman.
Peterman said stream flows near Wisdom have fallen to 10 cubic feet per second, well below the 20 cfs recommended point of closure under the Big Hole Drought Management Plan. This time of year, upper Big Hole River flows are normally at 320 cfs.
The Big Hole Drought Management Plan separates the Big Hole River into three "drought emergency" reaches. Today's closure encompasses the upper-most reach near Wisdom--a 19-mile stretch from Rock Creek Road to the mouth of the North Fork of the Big Hole. The stretch includes most of the river's critical grayling spawning and rearing habitats. The Big Hole Drought Management Plan was developed by the Big Hole Watershed Committee, a group of volunteers from agriculture, municipality, business, conservation, angling, and government interests.
Once abundant in the Missouri River above Great Falls, Montana's native fluvial, or river-dwelling, Arctic grayling are now restricted to the upper Big Hole River. The population represents the last remaining native population of river-dwelling Arctic grayling in the lower 48 states. Introductions of grayling into some Missouri River tributaries have recently been made to expand its present range.
Peterman said irrigators in the basin also are participating in the drought response plan and are already playing an important role in helping to keep water in the Big Hole River this summer. "In the past, during drought situations a number of irrigators have attempted to use less water than they were entitled to," he said. "The river and its fishery were helped through past droughts in better condition than we expected. This is a tough situation for these folks, and it's humbling to see their concern and their willingness to help. The fishing closure shows that anglers are as concerned as the irrigators. Anything we do now to conserve and protect these wild, native fish, will pay dividends three years from now."
Most Big Hole River irrigators will likely stop watering crops next week, which should result in better, yet still critically low, stream flows. FWP Fisheries Biologist Dick Oswald said he expects the lower reaches of the Big Hole River--from Mudd Creek to the Jefferson River--will likely be considered for angling closures later this summer.
Beginning in 1995, FWP and local Big Hole River water users defined emergency fishing-regulation guidelines and river- flow benchmarks that could influence angling opportunities when low-water conditions occur on the Big Hole. Those guidelines are now being followed as the Big Hole River flows continue to drop.
Peterman said the upper Big Hole closure will likely remain in effect throughout the summer.