This 14-barrel brew pub has 23 varieties of craft beer that rotate daily. Beer made on site makes for cheap flights and happy customers.

By the mid-1800s, the mill district in Saco and Biddeford was one of the largest cotton milling complexes in the country. At one point, nearly 9,000 residents were employed by the industry. And for three centuries prior, lumber was the primary industry – 17 sawmills were in operation by 1800.

Today, in building number three of the York Mill, built in 1838, the Run of the Mill Public House & Brewery is at the forefront of another budding trade – craft beer.

The Run of the Mill was the first craft brewery in Saco – Barreled Souls Brewing Co., set to open this summer, will be second.

The Run of the Mill is situated on the strip of Main Street that runs through Factory Island, or as the locals say, “the Island,” which is indeed a mass of land in the middle of the Saco River.

If traveling at night, you’ll see a huge, well-lit sign in front of a red brick mill building.

There’s free parking, but most nights, especially on weekends, the spots out front will be taken.

Inside, the first floor of the mill has been transformed into an expansive brew hall and eatery. The dining room can accommodate groups ranging from 12 to 100.

However, the main event is at the bar. Rebecca Lemieux, who has been working at Run of the Mill for nearly six years and is now general manager, said that on weekends the bar area is so crowded, people can hardly pass through. “It gets cozy in here,” she said.

On a recent weeknight, Lemieux looked down the bar, where at least 30 people were mingling, and said, “Out of all of the people at the bar right now, there’s not one I don’t know by name.”

And that kind of sums up the Run of the Mill – it’s a popular local hangout. Other than the fact that it has capacity for hundreds of people, beer lovers flock to the Run of the Mill because you can get craft beer here for cheap, which is one of the benefits of a brew pub.

Run of the Mill offers a 20-ounce “liberal cup” of house brew for just $3.75. Half pints are $2.75. With 23 rotating varieties, it’s hard not to order the flight of seven three-ounce pours for just $5.

A couple of the house brews stay on tap regularly, like the Bug Lager and the Alewife Ale, and there’s a full bar and wine list.

The food menu is a take on classic pub food, such as shepherd’s pie, bangers and mash, and meatloaf. But there are lighter options, like salads, soups, appetizers, sandwiches and even gluten-free options.

The kitchen tries to serve as many locally sourced ingredients as possible and most people would say it’s not-your-average pub food – it’s definitely at least a few notches above.

From Memorial Day to Labor Day, Run of the Mill opens up its deck, which is equipped with a separate bar and kitchen, and even a different “summery” menu.

Lemieux said a busy night in the summer can accommodate at least 100 on the deck.

And if that’s not enough, the Run of the Mill is also a meeting ground for local musicians. There’s live music from 8 to 11 p.m. Thursdays and Saturdays and open mic night from 8 to 11 p.m. Tuesdays.

Its popular trivia night from 7 to 9 p.m. Mondays usually attracts owner Geoff Houghton to participate.

The factories and mills of Saco and Biddeford may have closed down years ago, but with places like the Run of the Mill, a new life and a new era are certainly taking shape.

Claire Jeffers is a Portland freelance writer.