"We're ready just in case. I did grab a couple of things for my kids and our dogs, whatever I have to take, and I can go whenever they say we have to go," said Fontana resident Venus Woods.
However firefighters had the blaze 30 percent contained Wednesday night and expect full containment by 8 a.m. Thursday.
But until that time residents have no choice but to watch and wait.
"I won't be able to sleep until they get it out, because you can't rest with that type of fire behind you," said Jackie Curry.
Riverside County Sheriff's deputies briefly evacuated 32 units in the Santiago Estates Mobile Home Park as the grass fire moved toward the property. Firefighters were able to douse the threatening grass fire and residents were allowed to return home.
There were more than 200 firefighters on the scene and a water-dropping helicopter.
The fire continued burning eastward with 15 mph winds into a nearby hill.
No injuries or damage to structures were reported.