Missouri Gov. Jay Nixon on Saturday toured communities in his state ravaged by flooding that killed at least 31 people in several states and forced the evacuation of thousands in the Mississippi and Ohio river regions. Meanwhile, the danger of rising waters shifted to Arkansas and beyond.

Nixon visited Eureka and Cape Girardeau in eastern Missouri, where floodwaters caused widespread damage, and announced that he has asked the federal government to declare an emergency to help with the massive cleanup and recovery now under way.

"It's almost as if you're living on some other planet," he said, standing near a growing pile of debris in a park in Eureka, about an hour's drive west of St. Louis on the banks of the Meramec River, which flows into the Mississippi.

"This is just a tiny fraction of the trail of destruction," the governor told reporters.

The National Weather Service reported that Mississippi River floodwaters in Illinois and Missouri began cresting and receding on Saturday after thousands of people had to be evacuated from their homes earlier in the week, when the floods destroyed hundreds of structures.

Eureka homeowner Tracy Wolf, 58, spent the last three days trying to keep water away from his house with sandbags and out of his basement with vacuums.

"Wednesday night it came in through the windows," Wolf said. "We slept three hours the first night. ... I don't even know what day it is."

Twelve counties have been declared disaster areas in Illinois, where Gov. Bruce Rauner on Saturday toured several communities hard-hit by flooding. On Friday, he ordered Illinois National Guard troops into flooded areas to mitigate damage and help with evacuation.

The floods claimed the lives of at least 31 people in Illinois, Missouri, Oklahoma and Arkansas, most of whom drove into flooded areas after days of downpours.

Authorities continued searching on Saturday for country singer Craig Strickland, who had gone duck hunting on an Oklahoma lake during stormy conditions. His friend, Chase Morland, was found dead on Monday.

In Thebes, Illinois, about 125 miles (201 km) downriver from St. Louis, the floodwater was expected to crest at 47.5 feet (14 m) on Sunday, more than 1.5 feet above the 1995 record, the NWS said.

The flood warnings remained in effect on Saturday for parts of Tennessee, Oklahoma, the Carolinas, Alabama and Kentucky. Major flooding continued in Arkansas along the Arkansas River and its tributaries.

Arkansas officials said they expected the river, which bisects the state from west to southeast before joining the Mississippi, to crest late on Saturday.

Large swaths of parkland in Little Rock along the river were covered with floodwaters, and some homes and farmland in the Arkansas Delta were flooded on Saturday.

Signs that floodwaters were headed south began to emerge as the Weather Service issued a major flooding designation on Saturday for Osceola, Arkansas, where the Mississippi River reached above 35 feet (10.7 m), well above the 28-foot flood stage.

The agency also on Saturday warned communities in the Southern Mississippi Valley region of potential flooding during the next 10 days.

Officials in Louisiana are checking levees daily, and Exxon Mobil Corp. has decided to shut its 340,571 barrel-per-day refined products terminal in Memphis, Tennessee, as floodwaters threatened to inundate the facility just south of the city's downtown.

Workers in southwestern Tennessee prepared sandbags in hopes of limiting damage from the Mississippi when it crests at Memphis next week, state emergency management officials said.