Update, 7 a.m. Monday:
The fire is 100 percent contained as of about 8:20 p.m. last night, according to Cal Fire. Due to more accurate mapping, authorities updated the acreage burned to 25 acres.
A vegetation fire near Johnson Ranch in San Luis Obispo burned 30 acres Sunday morning, according to Cal Fire.
The fire — which was visible from Highway 101 — was reported at about 10 a.m. in the 6200 block of Ontario Road and was threatening two structures, Cal Fire said.
About an hour later, crews stopped forward progress on the fire and mitigated the structure threat, according to Cal Fire spokesman Chris Elms.
By early afternoon, the fire was 50 percent contained, according to Cal Fire.
No injuries were reported in the fire and no structures were lost.