RICHARDTON (AP) - It was a cold December day when the Red Trail Energy LLC ethanol plant started grinding corn to make ethanol.

It will be a pre-autumn afternoon that marks the facility's grand opening.

The ceremony is set from 10 a.m. to 3 p.m. on Friday.

Since production began, the plant has created a new eastern skyline for the town and a new interest for many others.

"The plant is a well sought out project with school groups, local visitors and business groups coming for tours," said DeEll Hoff, the plant's accounting and marketing manager. "We constantly have bystanders coming off the interstate wanting to know what kind of plant this is and wanting to see it. People bring friends and families to see it."

Plant staff is expecting up to 400 people for the grand opening, Hoff said. After months of work, the plant is ready to officially welcome the public.

"We wanted to wait for nice weather and to make the grounds presentable," CEO Mick Miller said. "Staff has worked diligently to make it look presentable."

In the beginning, employees were taking people through the plant as much as they could, but it wasn't efficient for employees, Miller said. Tours were scheduled about once a month.

"That's why we wanted to have a day for as many people to come and see it at one time and get as many through as possible," Miller said. "We also want our employees to meet their surrounding neighbors and people of interest."

Tours cover the basic ethanol-making process. As people walk through certain areas of the plant, employees indicate points of interest related to the process.

Tours are free, and groups have included everyone from farmers and seed dealers to fire departments and legislators, Miller said.

"Since we've opened, we've probably had upward of 1,000 people go through the site already," he said. "Businesses and other organizations like to have meetings using our conference room and the opportunity to tour the plant."

A new addition to the landscape around the plant is about 25 acres of corn plots. Miller said Red Trail Energy is growing 11 different corn varieties.

"We want to see what grows best in our area," he said. "We can show what corn grows here and that we encourage it. Red Trail Energy LLC is a market, grinding 18-20 million bushels a year."