Greg Bostater of Portland wanted a brown trout challenge. So he packed up his drift boat Friday and headed to the Delaware River in New York, where the hard-to-hook fish grows up to 30 inches.

Maine is not a hotbed for brown trout, which are stocked and not native. However, the state is working on changing that by trying to come up with a strain of hatchery-raised browns that are robust and more catchable, or at least more prolific.

Department of Inland Fisheries and Wildlife biologist Francis Brautigam said the state has been working since 2003 to come up with a brood stock that will show better “field performance,” especially in terms of survival and abundance. IFW is testing a strain of brown trout from Massachusetts, another from Connecticut, and one created from eggs from different states (called the New Gloucester strain after the fish hatchery located there).

The study will continue until 2020 before biologists decide the best brood stock to use in Maine, Brautigam said. They’re surveying anglers and fishing the stocked waters themselves to determine the overall health of fish from each strain, and to see how those fish performs in the wild and in the hatchery.

“All three assessments will be considered in assessing the future fate and role of brown trout in Maine’s fishery management programs,” he said.

Browns are inherently hard to catch, Brautigam said, because they are selective in their feeding habits. Once hooked, a brown will fight hard.

“They typically offer relatively slow fishing by comparison to other species,” Brautigam said. “But because they are more difficult to catch, they tend to be less vulnerable to harvest and survive to grow to larger size.”

Some fishermen don’t fish for browns specifically because they’re not a native Maine fish.

“(Trout Unlimited) favors native species. In Maine, that means brook trout, landlocked salmon and lake trout. (The state) only stocks browns in places where they just can’t get the natives to provide fishable abundance. It’s safe for me to say that TU generally supports this position,” said Steve Heinz with the Sebago Chapter of Trout Unlimited.

However, Jim Bernstein, manager of Eldredge Bros. Fly Shop in Cape Neddick, loves the challenge of fishing for browns. He said trying to get a “smart fish” to take his fly has become his favorite part of fishing, and browns offer that challenge because they are so particular in what they eat.

“I’m not referring to freshly stocked browns, I’m talking about browns that have grown up in the rivers or tidal waters they are living in. Brown trout can be the most wary species of trout that you will fish for,” Bernstein said. “But once hooked, brown trout can give a tremendously hard fight and make huge leaps from the water. They also can grow really big.”

The world record for brown trout is 42 pounds, 1 ounce. The 20-year-old state record is 23 pounds, 5 ounces.

Bostater, a guide for 20 years, said good brown trout fishing can be had in Maine if you know the rivers, the fly hatches and the exact fly the browns want, but there are better fisheries in the East.

“Brown trout are not native anywhere in the U.S. There is not a single state where they’re native. Maine does an OK job (stocking browns), with the Kennebec probably being the best known fishery,” Bostater said. “But the Delaware River (in New York) is probably the best brown trout fishing in the eastern United States. They have good-quality brown trout in the 20-inch range and up to 30 inches. And they simply have more per mile in that river, and they’re more robust.”

For Bostater, the challenge in the chase is the reason he drove to southeastern New York this weekend to try to hook a monster brown.

“I’m expecting to be humbled on the Delaware River,” he said. “The river might be blanketed with bugs. There might be eight different insects out. But the browns may only be feeding on one or two. You have to spend time paying attention.”

Fly fisherman Al Lindberg of Gray also hunts for the better brown trout waters in Maine.

“I fish a lot of areas on the Androscoggin, areas nobody else fishes. These fish are able to winter over and they are bigger,” Lindberg said. “Whether it’s fortunate or unfortunate, they’re here. I’ve never looked at a fish’s pedigree. I’m 70 years old. For me, it’s about the tug on the end of the line.”