MINNEAPOLIS — Many of Minnesota's most popular lakes still have ice as the state's fishing season opener approaches on Saturday, but one of the coldest and snowiest Aprils on record has given way to a warm, sunny May that's causing rapid melting and giving hope to anglers, resorts and bait shops.

Some 500,000 anglers traditionally fish on the opening weekend, the kick-off to Minnesota's summer tourism season. Here's a look at what's happening and what's new for the 2018:

THE LATE ICE-OUT

April was so cold that the ice grew thicker on some lakes instead of deteriorating as it normally does. As of Friday, most big walleye lakes across the northern half of the state still had ice, including Mille Lacs, Leech, Winnibigoshish, Red, Vermilion, Kabetogama and Lake of the Woods. But many smaller lakes have opened up in the last week alone, the Department of Natural Resources' ice-out map shows.

That doesn't mean there won't be fishing in the north, where bays and shorelines are starting to open up. For example, the Rainy River is completely open and there's open water past the gap where it flows into Lake of the Woods.

Lundeen's Tackle Castle rates prospects for the opener on Mille Lacs Lake as "iffy," but Lyback's Marine expects the ice to disappear fast.

Ice fishing probably isn't a good idea, even if it looks feasible. The DNR advises extreme caution, or staying off altogether.

"Ice this time of year is dangerously deceptive and can change markedly in a matter of minutes — and within just a few feet," DNR enforcement chief Rodmen Smith said in a statement.

Bait is likely to be an issue for the opener. Much of Minnesota's minnow and leech supply comes from northern lakes and ponds.

NEW NORTHERN PIKE REGULATIONS

Minnesota has given its northern pike regulations a complete revamp for 2018. The old statewide daily limit of three has given way to three distinct zones with different rules designed to take down the surplus of small "hammer-handle" northerns in many lakes while protecting the fierce predators elsewhere.

Most of Minnesota lies in the north-central zone, where limits will rise to 10 to encourage anglers to keep more small northerns. No more than two can be longer than 26 inches, and all from 22 to 26 inches must be released. In the northeast zone, anglers can keep two but must release all from 30 to 40 inches, and can keep only one over 40 inches. In the southern zone, anglers can keep two pike, with a minimum size of 24 inches. So be prepared to measure.

The new zones don't apply to border waters. Special regulations are in place for more than 90 individual waters, so check the 2018 rulebook.

MILLE LACS LAKE

Once considered Minnesota's top walleye lake, Mille Lacs Lake is facing its third consecutive catch-and-release-only season for walleye. The DNR hopes this will allow fisheries managers to keep it open to walleye fishing all year, instead of closing it as they did for a month last summer.

Mille Lacs' walleye population has undergone a long-term decline that has coincided with significant changes in the lake's ecosystem, though the DNR says its spawning stock has shown signs of improvement. But the lake has become one of the country's top bass fisheries, with a thriving smallmouth population.

THE GOVERNOR'S OPENER

Gov. Mark Dayton is guaranteed open water for the official 2018 Minnesota Governor's Fishing Opener. The annual event is being held in the Willmar Lakes Area of west-central Minnesota. Dayton is due to fish Saturday on Green Lake, which recorded its ice-out Thursday. There were still 29 inches of ice on the lake just 18 days earlier.

Dayton's guide will be local resident and anger Kelly Morrell, who considers Green Lake to be his home base.

"Green Lake is the jewel of Kandiyohi County. At 5,000 acres, it is the largest body of water and also includes the largest variety of fishing habitat. It is a fisherman's dream lake," Morrell said in a statement.