The Hewlett Gulch Fire continues to burn, Tuesday, May 15, 2012, in the Poudre Canyon near Fort Collins, Colo. The U.S. Forest Service said Wednesday that the blaze northwest of Fort Collins was caused by humans and the investigation is continuing. About 200 firefighters are now fighting the blaze, which is only about 5 percent contained. (AP Photo/The Denver Post, RJ Sangosti) MAGS OUT; TV OUT; INTERNET OUT

FORT COLLINS | More evacuation notices have been issued as a wildfire in northern Colorado continues to grow.

The Hewlett Gulch Fire continues to burn, Tuesday, May 15, 2012, in the Poudre Canyon near Fort Collins, Colo. The U.S. Forest Service said Wednesday that the blaze northwest of Fort Collins was caused by humans and the investigation is continuing. About 200 firefighters are now fighting the blaze, which is only about 5 percent contained. (AP Photo/The Denver Post, RJ Sangosti)

The blaze northwest of Fort Collins is still only about 5 percent contained, and has grown to nearly 1,000 acres. About 200 firefighters are expected back on the fire lines on Thursday.

Two groups of residents have received notices to be prepared for possible evacuations, but no one has had to leave. The fire is within a quarter mile of some homes.

The U.S. Forest Service says the fire was caused by humans. The investigation into how it started is continuing.

In western Colorado, firefighters expected to have a 170-acre fire between Delta and Whitewater fully contained sometime Friday. That fire was started by lightning. No structures are threatened.