That is one mile south of the Morrison.
According to the Colorado Department of Transportation, (CDOT) southbound US 285 was closed at C-470 while the boulder was in the middle of the road.
The boulder fell just before 6:30 p.m.
CDOT used a special piece equipment to break apart the rock and clear the road.
The road reopened around 10 p.m. on Friday.
CDOT spokesperson Mindy Crane says the heavy rains could have dislodged the boulder, but the cause will not be clear until experts look at the site.
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