– Dave Ruis scooped a pound of jumbo leeches for a customer at 65 Bait and Tackle, drenching the slithering clump of fish food with a cold pint of water and sealing the poly bag with a rubber band.

By the time he walked to the cash register, four more fisherman had joined the waiting line in front of his service counter. It stretched out the door to a gravel parking lot filled with pickup trucks and trailered boats heading north to Mille Lacs and other destinations.

“We’re super busy,’’ said his co-worker, Krystal Vradenburgh. “It’s like a factory line.’’

At this popular roadside stop along Hwy. 65 and at various places along the southeastern waterfront of Mille Lacs, there was tangible excitement for another Minnesota fishing opener as anglers made their final preparations.

“This is when it starts to get crazy,’’ said Amelia Andrews, at work in Isle at Da Boathouse Restaurant and Bar shortly before dinner on Friday.

Walleye fishing on Mille Lacs has taken a beating over the past three years, with midseason closures, no-fish bag limits and bans against night fishing. The tight regulations stem from scientific evidence of scarcity, but the lake just finished another successful season of ice fishing, biologists last year estimated a surge in the population of walleyes 14 inches or longer and the Department of Natural Resources has opened a temporary, one-walleye bag limit until June 1. (Keepers have to be 21 to 23 inches long, or more than 28 inches.)

“Just being able to keep something makes a big difference,’’ said Kevin McQuoid, owner of Mac’s Twin Bay Resort. “This first part of the season is going to be fun.’’

Mille Lacs is Minnesota’s second-largest lake and the object of intense scrutiny as a still-remarkable walleye fishery that has undergone changes that have included infestations of nonnative zebra mussels and spiny waterfleas. The invaders have disrupted the lake’s food web and added to unwanted water clarity.

But McQuoid and others sense that this year’s opening week of the season will keep Mille Lacs on a positive roll. Word will spread quickly if the early walleye fishing is as strong as predicted, he said.

“There’s no doubt the fishing is going to be great,’’ said Dave Estrem, manager of Hunter Winfield’s Resort on Isle Bay.

Water temperatures on the south end of the lake were on the cool side for the opener — below 50 degrees in many spots. But Brian Houston, a veteran boat captain on Mille Lacs and the skipper of the 30-person launch boat at Hunter Winfield’s, was looking forward to a strong bite. He planned to depart with his first group of anglers — members of a bachelor party — at 8 a.m.

“I haven’t needed my filet knife for a couple of years so I had to go find it,’’ Houston said. “It’ll be different coming in with fish to clean.’’

Houston grew up in Austin, Minn., but spent time on the lake as a boy during family visits in the 1970s. He can recall the days when resort owners rolled wheelbarrows onto their docks to unload walleyes from returning launch boats.

“It’s been a desert here the last few years with this catch-and-release stuff,’’ Houston said.

At Father Hennepin State Park, Monte Lawrence admired the steady stream of boats and trailers being wheeled in on Friday afternoon. The mood around campfires was festive, and his own group was hoisting an American flag 25 feet into the air on a collapsible pole.

He said the one-fish limit is drawing more people to Mille Lacs this year, but it didn’t matter to him.

“Catching them is the most fun,’’ Lawrence said. “It’s all about catching them.’’

His son, Brandon Lawrence, was rigging fishing lines while perched in a brand-new Ranger boat parked on its trailer in view of Mille Lacs. His plan was to launch at 5 a.m. and fish deep, away from all the boats expected to congregate near shore in 4 to 12 feet of water.

“We’ll look for some big ones out there,’’ Lawrence said. “But the plan always changes.’’

Ruis — the clerk at 65 Bait and Tackle — said he grew up fishing on the south end of Mille Lacs on such spots as Indian Point and Rocky Reef. But he’s since shifted his walleye fishing to smaller lakes, away from crowds and busy boat ramps.

“Mille Lacs is turning into a trophy lake, and that’s OK,’’ he said.

There’s no doubt, he said, that the big lake has plenty of walleyes worthy of a trip to the taxidermist.

Ruis hurried to eat a bowl of soup during a short work break. One of his co-workers, John Rasmussen, stepped behind the counter to help out. The fishing opener on Mille Lacs and other area walleye lakes is still a spectacle, he said. This year there’s an uptick and there have been some orders for $200 to $300 worth of minnows, crawlers and leeches.

On Friday before the fishing opener, he said, the shop has its own tradition.

“We’ll be open until midnight.’’