If you take a drive down scenic 79 just outside of Hannibal, there's a reminder at the base of the cliff to keep your eyes open for falling rock where a boulder fell earlier this year and authorities brought another one down to keep it from falling.
You might recall authorities blaming rainfall for its breaking loose and hitting the road below just a couple car-lengths in front of one driver.
With even more rainfall lately and more to come, MoDOT Engineer Brian Haeffner says while it isn't an immediate threat, drivers should keep an eye out for even more falling rocks.
"The rain that mother nature gives us has a lot of effects on us," said Haeffner. "Not just the flooding, but there's also the potential for slides or falling rock when we get this much rain so it's something that we have to watch out for."
Haeffner says conditions are right to see some potential hazards.
"Those are loosened up through the winter through the freeze-thaw cycles, but then when you get a lot of rain the earth underneath turns to mud and it can slide off and that's what causes it to fall off," said Haeffner.
Haeffner says everyone on the roadway should use caution.
"If you're out there on the road you need to be paying attention to the road itself, to traffic, and then what's going on around you so if there's any signs that something's coming down it'd be a good idea to keep away," said Haeffner. "If you're running you might go on the opposite side of the shoulder."
He says sometimes if you're paying attention you might even be able to notice plants sliding first or smaller rocks and that if you see any of that, he says you should not drive into it.
Haeffner says you should also call 911 if you see dangers like those and let them know.