What makes the Yellowstone River so special? Perhaps it's because the Yellowstone is the longest free-flowing river in the continental United States.
The Yellowstone’s 671-mile journey begins from headwaters in northwestern Wyoming, enters Yellowstone National Park and flows into Montana near Gardiner. From there, the river runs across south central and Eastern Montana, ending downstream from Sidney where it enters the Missouri River in North Dakota.
For more than 70 miles, the Yellowstone travels through Yellowstone County, where the river played a key role in the founding of Billings more than 100 years ago.
The Yellowstone continues to shape and influence development of Montana’s largest urban area. A 2013 estimate from the U.S. Census Bureau pegged the countywide population at 154,162 people.
While offering fishing, boating and other recreational opportunities, the river's also a workhorse that drives the local economy.
The river is essential for the operation of the county’s three oil refineries, power plants and other industries. The Yellowstone irrigates thousands of acres of cropland in the Yellowstone Valley. And the river provides drinking water for most Billings, Laurel and Lockwood residents.
Because of how Billings developed early on, the city is not as connected to the Yellowstone as cities like Missoula and Great Falls are to their rivers, said Kevin Kooistra, community historian at the Western Heritage Center.
“Our relation with the river is not the idealized Missoula thing where you see the fly fishermen along the banks. It’s very odd,” Kooistra said. “We’re kind of pulled away from the river."
When the townsite of Coulson was first established in 1877, it was along the river, where the Rimrocks “pinched together” along the banks of the Yellowstone in the area of Coulson Park, Kooistra said.
But Coulson faded away in 1882; the year Northern Pacific Railroad officials established Billings west of Coulson and built a railroad.
Railroad officials platted Billings in 1882 using section lines that went north of the tracks and away from the river instead of following the river, Kooistra said.
Town developers tended to reserve the southeast area for industry, putting odorous businesses, like feedlots and sugar plants, south of the tracks and downwind from the community, Kooistra said.
“In some ways, what’s interesting about our town is that the industry has kind of severed us from the river. I almost see it now like a barrier separating the city from the river,” he said.
Today, the county's oil refineries, a power plant and sewage treatment and municipal water plants abut the Yellowstone’s banks.
While the community has developed park land and trails along the river corridor, Kooistra said business growth also is occurring by the river.
“We continue in some way to sever ourselves from the river. It’s like the Rimrocks are really the more notable and, in some ways, natural feature, it seems. And the river is like a mystery,” he said.
The Yellowstone also changes as it travels through the county, transitioning from cold water to warm water, which affects fisheries, said Bob Gibson, a spokesman for the Montana Department of Fish, Wildlife and Parks.
“The real transition is Laurel,” Gibson said, where the Clarks Fork River enters the Yellowstone from the south. The Clarks Fork is warmer, carries more return irrigation water and has more sediment than the Yellowstone, he said.
While there is “not a clear break,” Gibson said, trout, which like cold water, are found more upstream from Laurel, while warm water species, like catfish and bass, live downstream from Billings toward Huntley.
Fishing between Laurel and Duck Creek, “you can catch a trout or you can catch a bass,” Gibson said.
“We’ve got a really nice population of sauger that lives below Billings in the Yellowstone River. They are a native species,” Gibson said.
The county’s sauger population is “genetically unique” and it has not mixed with any other sauger population, he said.
While many people fish the river in Yellowstone County, the stretch is not a “destination fishery” like the Big Horn River or Fort Peck Reservoir, Gibson said. “It’s much more of a local fishery,” he said.
A 2011 oil spill that dumped an estimated 63,000 gallons of crude oil in the river by Laurel when an ExxonMobil pipeline broke during high water flows still causes some concern, but the riparian area is healthy, Gibson said.
“The river seems to be recovering somewhat” from the oil spill, Gibson said. Biologists continue to monitor the fisheries for evidence of petroleum poisoning, he said.
The oil spill, which cost ExxonMobil more than $135 million in cleanup costs plus environmental penalties, triggered lawsuits and drew national attention.
“That was absolutely a big event,” said Karin Boyd, who owns Applied Geomorphology Inc. of Bozeman and has been studying the Yellowstone River as part of a cumulative effects study being conducted the Yellowstone River Conservation District Council.
“I think the oil spill and how it hit the national radar so fast" showed the Yellowstone's allure, Boyd said. "It really got people’s attention,” she added.
There is a national perception, Boyd said, that Montana’s rivers are “a very pristine resource. We know that they’re not.”
Boyd, who has helped map the entire river, said the river in Yellowstone County is noted for the extent of development and bank armoring along the corridor from the Clarks Fork to Billings, about 15 river miles.
“We have the whole suite in Yellowstone County,” Boyd said.
Materials used to armor the bank for erosion and flood control include car bodies, concrete riprap like old sidewalk, rocks, levies and dikes, Boyd said. In that reach, she said, the banks have 942 feet of car bodies, also known “Detroit riprap,” which were used before the 1970s.
Between 1950 and 2005, the proportion of bank affected by armoring increased from 4 percent to 25 percent, Boyd said. By 2005, about 80,000 feet, which is about 15 miles, was affected by bank stabilization and flood control efforts.
Bridge construction has constricted the Yellowstone’s natural meandering corridor, making the corridor in that reach narrower and causing the river to carve a deeper channel, Boyd said.
And the river has lost major side channels both from the installation of dikes and riprap and from the down cutting, Boyd said. Losing side channels had led to new riparian areas, which can be beneficial, but it also can lead to infestations of Russian Olive, an undesirable, invasive non-native tree.
The Yellowstone used to have many channels in that area, so many, Boyd said, that “you couldn’t tell which was the main channel. Some people call it a split main.” Now there tends to be a dominant main channel, she said.
The cumulative effects study is partly aimed at determining the implications of that. "What we really look for is whether there is a balance," Boyd said. "We are trying to objectively characterize those impacts."
Population growth in the Billings area also has contributed to converting lower-value agricultural land uses to higher-value urban uses, said Boyd in her research.
But for all the bank stabilization efforts, the Yellowstone continues to assert its power as a free-flowing river. The most recent reminder came in 2011, when prolonged flooding caused widespread damage.
“We saw a fair bit of bank armor failing” in the reach between Laurel and Billings, Boyd said. The river took out or flanked about 2,900 feet or about 10 percent of concrete riprap. “That’s a lot,” she said.
Downstream at the Huntley Irrigation Project, the 2011 flood ruined a concrete culvert on Pryor Creek, putting Huntley area farmers at risk of losing irrigation water from the Yellowstone. Repairs cost about $2.4 million and were designed to allow for fish passage of a previously blocked creek.
The Huntley Irrigation Project provides river water to irrigate more than 30,000 acres of sugar beets, barley and corn.
Further downstream, below Pompeys Pillar, Boyd said, the Yellowstone migrated 700 feet into a field, prompting emergency protection for a house.
Overall, the river in Yellowstone County is “pretty healthy,” Boyd said. “There’s always the risk of that trend declining. But it is hanging in there,” she said.