Here's a few things I found on the net.
It looks like it has been up for 20 years, it is called "The Dauphin Narrows Statue of Liberty", placed by Gene Stilp, it's initial appearance caused more than just a stir, auto accidents were common as people were shocked to see Lady Liberty on the old bridge structure, and last year Dauphin County actually declared July 12,2006 as Lady Liberty Forever Day in recognition of the statue's 20th anniversary.
The creator Gene Stilp is a nationally known activist on behalf of environmental, energy and consumer causes. Tilp's more memorable publicity stunts include a giant inflatable slot machine to oppose plans to legalize slots at the state's racetracks. To protest President Bush's clean-air policies, he created a pair of 17-foot coal-fired power plants, attached by Velcro to a replica of the White House. Stilp wrote and recorded the "Tom Ridge Liquor Plan Polka" to protest the then-governor's plan to privatize the state's retail liquor business. He assembled a 30-foot ear of corn with milk-jug kernels for a 1999 Food and Drug Administration hearing on genetically modified crops. And he towed a giant smoking toaster - a converted 1963 Airstream trailer - to the Capitol in 1998 to oppose a bill favorable to the nuclear-power industry.