The state of New Jersey and Mercer County have forged an agreement that will keep the Petty’s Run archeological site in Trenton open. The county and the state Department of Environmental Protection will invest an estimated $1.6 million in the next 10 years in the site. The county’s contribution of $800,000 will come from its Historic Preservation Trust Fund. The state will invest another $800,000 to the project, $400,000 of which was originally intended to be used to close the site. By keeping Petty’s Run open, and developing the site, both the state and Mercer County hope to provide educational opportunities and increased tourism in Trenton.