BELFAST — What is happening on Route 3?

The question has been on the minds of many in Belfast in recent weeks, as the rumor mill has started churning in response to a flurry of activity on previously undeveloped tracts of land — including an 85-acre parcel the city designated a few years ago as suitable for a big-box retailer.

City planner Wayne Marshall said Monday that no applications have been filed to date for the parcel across from the Bank of America campus, even though surveyors have been working there. The land was purchased years ago by New Hampshire-based developers Bob and Gary Bahre, who owned the New Hampshire International Speedway until 2007. Along with the Reny’s property about a half mile away, it is one of the only places in Belfast where a large retail store could locate.

“I’m sure there’s always speculation about what individuals may or may not be doing,” Marshall said. “Things happen that you may not know about until the day someone walks in and says here’s what we’re proposing to do.”

The city of Belfast debated big-box stores for more than a decade — sometimes hotly — before officials finally decided in the mid-2000s that the Route 3 parcel was the best place. There are many stipulations tied to any development, though — including the city’s requirement that the owners first submit a master plan. It is the only property in town whose owners must follow that requirement, but that doesn’t assuage the fears of some, including Denise Pendleton. The Crocker Road woman lives in her childhood home, which abuts the Bahre parcel, and she said she is worried about increased traffic, decreased property values and the alteration of a beautiful wooded spot.

“I think if I were really wealthy, I’d buy it and turn it into a land trust,” she said last week. “There’s great trails back there. There’d be a great place to pull in and park. It would be a great place to welcome people to the city. Everybody going to Bar Harbor drives past that, and I think it has such potential to promote the town.”

Another eye-catching spot on Route 3 that has recently changed hands is located west of the Bahre property on Hayford Hill. The large field with an expansive view of Penobscot Bay has finally sold after spending years on the market. Waldo County residents Dan and Amy Miller, operating as Seahorse Stables, are constructing a large indoor riding arena at the far corner of the 27-acre site. The owners are building a 25,000 square foot structure with an attached stable, which will contain room for 10 to 12 horses, according to Marshall. He said that construction on the estimated $2 million property is likely to take a year to complete.

Another property on Route 3, a 1.4 acre parcel next to athenahealth, also recently sold. The owners have met with city planning office staff to discuss a “small retail establishment” project, Marshall said. Additionally, a woman recently demolished an older home on property located right next to the Bahre lot, and a parcel across from EBS is now under contract.

“Clearly, people are looking around,” Marshall said.