A brutal winter across most of the Midwest that featured plenty of snow, ice and bitterly cold temperatures left ice jams in the river as spring approached. As the weather warmed, the melting ice combined with spring rains to create high water levels along lengthy stretches of the mighty Mississippi.

As a consequence, some mines in southern Illinois were forced to temporarily close when barges became unavailable. Others kept producing but found deliveries backlogged when they also could not secure enough barges to move their coal downriver to the neighboring Ohio River and other major waterways in the region.

Peabody Energy, for instance, temporarily idled its Wildcat Hills underground mine and Cottage Grove surface mine in March in Saline and Gallatin counties. The mines are among the largest producers in southern Illinois, turning out a combined 4 million tons of high-sulfur coal in 2014, according to the Mine Safety and Health Administration. They also employ more than 420 people.

Charlene Murdock, a spokeswoman for St. Louis-based Peabody, the world’s largest private-sector coal company, confirmed that Wildcat Hills and Cottage Grove were idled because of high water in the Mississippi that left barges inoperable. The mines were operating as normal in April.

Knight Hawk Coal had a similar problem. The company, which operates several surface and underground mines in southern Illinois, also owns the Lone Eagle dock on the Mississippi near Chester, Illinois. Shipping was adversely affected after Knight Hawk also encountered difficulties in finding enough barges to send its product to market. Knight Hawk did not curtail production, however.

The end result, the company said, was an approximately 55,000-ton backlog it had planned to ship in the first quarter but was prevented from doing so by the river.

Early in the second quarter, Knight Hawk was still trying to catch up on shipping. “We’re working toward that, but I can’t say we’ve made a huge dent in that,” said Josh Carter, the company’s vice president of operations.

Carter surmised it probably would take Knight Hawk until sometime in the third quarter to eliminate the backlog.

Knight Hawk expects to hit the 5-million-ton production mark this year for the first time. It produced about 4.8 million tons in 2014.

Coal shippers on the Ohio River were not totally spared either. In late April, Ohio County Coal Company blamed high water levels for its decision to temporarily idle the West Virginia underground steam coal mine formerly known as Shoemaker.

Ohio County Coal is owned by Murray Energy of St. Clairsville, Ohio. In late 2013, Murray, the largest privately owned coal company in the U.S., acquired Shoemaker along with four other underground mines in West Virginia from Consol Energy in a $3.5 billion transaction.

Shoemaker produced nearly 6.6 million tons of coal in 2014 and almost 1.6 million tons in the first quarter of 2015. The mine has nearly 600 employees.

Murray expects to produce 65 to 66 million tons of coal this year.