GILLETTE, Wyo. (AP) _ Most families who were evacuated after build-ups of toxic gas were discovered have returned to their homes, but some residents say they are still worried.

''My kids are wanting to move,'' said Diane Savage. The youngest of her seven children have had nightmares since investigators began testing the soil around their subdivision for gas, she said.

In February the presence of methane inside some homes and hydrogen sulfide between two houses prompted Campbell County officials to order evacuations of 31 of the neighborhood's 215 families.

About two weeks ago the county decided that all but seven families could return.

Ranchers noticed gas bubbling up in Rawhide Creek before the Rawhide Village subdivision was built 12 years ago. This year, methane began seeping through a coal seam beneath lawns in this northeastern Wyoming community.

Ten-year old Chenel Altman and her family recently moved back to Rawhide Village, but she'd rather live somewhere else.

''Then you wouldn't have to worry about dying,'' said the fifth grader at Rawhide Elementary School.

''There shouldn't have been a subdivision built here,'' said Mrs. Savage, pointing to soil test results taken before construction began that indicate some lots are as little as a foot above the coal.

But a company that recently studied the soil said it is unlikely the problem could have known before construction.

''Obviously nobody considered it so they must have been ignorant at that point,'' said Chester McKee, president of In-Situ, Inc. Possible gas seepage was not a criterion when the permitting process was begun for the subdivision, he said.

The methane apparently built up naturally, and if so, there may be no solution to the problem, McKee said.

''If (the contamination) is due to natural causes, then it's hard for me to see that it is possible to solve it,'' he said.