ST. LOUIS • An atheist is suing to force the administrators of a towering cross in Southern Illinois to return a $20,000 state grant toward its restoration, saying Thursday it was "blatantly unconstitutional" to spend taxpayer money on a Christian symbol.

Caretakers of the 11-story Bald Knob Cross of Peace near Alto Pass, Ill., about 130 miles southeast of St. Louis, insist the grant was legally awarded to the 50-year-old landmark in mid-2008 by classifying it as a tourist attraction, not a religious symbol.

Rob Sherman disagrees, pressing in his federal lawsuit in Springfield, Ill., that the grant violates the U.S. Constitution's establishment clause used to argue a separation of church and state.

"There has never been any question, outside of Southern Illinois, that this state grant is blatantly unconstitutional," said Sherman, who successfully sued to have an Illinois law requiring a daily "moment of silence" in Illinois public schools overturned.

"The job of atheists is to take clergy to court to challenge the epidemic of civil wrongs that they have perpetrated, on the sneak, against the people of Illinois," Sherman said on his website. "It's a big job, but somebody's gotta do it."

In his lawsuit filed Thursday, Chicago-based Sherman asks a judge to compel the caretakers of the cash-strapped cross to return the money or face what he pledged would be a drawn-out, expensive legal tangle.

Steve McKeown, a pastor and administrator of the cross, said he was confident Sherman would not win. He said Bald Knob drew roughly 1,000 visitors last weekend, underscoring its sway as a tourist draw.

"What Mr. Sherman fails to recognize is there's a long-standing precedent for the fact that just because an organization may have a sectarian purpose, it does not exempt them automatically from receiving tax dollars," McKeown said.

"What Mr. Sherman wants is a United States that's free from religion," McKeown said. "Our founding fathers never meant that to be the case."

The cross — built in large measure with area farmers' profits from selling pigs — has been a fixture on the 1,025-foot-high Bald Knob Mountain for a half century, standing sentry over forests and much of the region's orchards and burgeoning wine country. Easter services have been held on the mountain since 1937.

No hearing date was immediately set.