Earlier this week, the mayor sent a letter announcing his "vigorous opposition" to the proposal to 180 people, including lawmakers and parks board members, who will vote later this month on the plan.

"This Is the Place Heritage State Park is a reflection of the proud history of Utah's pioneer settlers and, as such, deserves our full protection," Anderson wrote in his letter.

The mayor also hopes the City Council will join him by signing a resolution against leasing 12 acres of the park, at the mouth of Emigration Canyon, to ARUP Laboratories to build an administrative building and parking lot. The council could discuss a resolution Tuesday, or members may send letters individually.

Council Chairman Van Turner says the council would probably oppose the land lease, but says the issue does not affect some council members. He represents the city's southwest quadrant, for example.

"I don't think anybody wants to get rid of any open space. We're buying it," Turner said.

The mayor's tough stand comes a year after he and a council majority supported rezoning open space to allow Rowland Hall-St. Mark's School to eventually build a school on land owned by Mount Olivet Cemetery.

Councilman Soren Simonsen, who voted against the cemetery rezone, said the situations are the same: Both Mount Olivet and This Is the Place need money and propose selling off open space to get some. He is glad to see the change of heart among council members.

"I would love to see it stay as some sort of publicly accessed space," Simonsen said of the heritage park, suggesting the city could help buy the land with some of its $5 million open-space fund. "It has a lot of value to the community."

Managers of the heritage park, which re-creates Mormon pioneer life from 1847 to 1897, want to lease the land to stanch the park's financial bloodletting. It suffers from poor attendance and received a $2 million bailout from the Legislature last year.

Noting the ARUP office building would stand near the restored farmhouse of Mormon pioneer prophet Brigham Young, Anderson said the development would "result in permanent and irreparable harm to the park and may well set a precedent that would be used to allow further unwanted development in the future."

The mayor sent his letter a day after Utah Jazz owner and park benefactor Larry Miller criticized the land lease as trying to "sell our future to save our present."

hmay@sltrib.com