UPDATE (9 a.m.):

US 20/WY 789 through the Wind River Canyon is now open, though WYDOT says one lane is closed and traffic control is being implemented. 

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A large rock fell across a Wyoming highway Wednesday night, forcing an overnight road closure as crews continue to try and clear the roadway.

As of 8 a.m. Thursday, US 20/WY 789 between Shoshoni and Thermopolis remained closed with no estimated reopening time.

WYDOT spokesman Cody Beers said crews worked all night and were still working Thursday morning to break up the large rock that fell just east of the Boysen State Park Headquarters.

Heavy rains over the past several days have caused rock falls on other Wyoming highways, including US 14 and US 14A, portions of which were closed for over a day.

Flooding has also caused damage and displaced families in communities such as Sheridan.