Money is the main reason the DNR no longer will supply fish after this year, Early said.
He said that raising enough fish to annually stock about 85 events across the state takes one "man year": 40 hours a week for 50 weeks, or 2,000 hours.
Some local organizers said the rodeos are too important to stop and have vowed to buy their own fish.
Those groups that can't afford the added cost - potentially hundreds or thousands of dollars - may stop their events.
"That would be very, very unfortunate," said N. Linn Hendershot, who is coordinating two fishing events for children, senior citizens and people with disabilities. Many Individuals Helping Individuals, or MIHI, is a sponsor of the events.
Wade Moore, who manages the DNR's Albert M. Powell State Fish Hatchery southeast of Hagerstown, said community groups likely would pay private suppliers about $2 or $3 per fish instead of getting them free from the state.
Washington County groups have many fishing rodeos each year - in Hagerstown, Boonsboro, Sharpsburg and Williamsport, to name a few.
A rod and gun club and a conservation club held rodeos Saturday; the season is getting in gear.
The work and money that goes into supplying rodeo fish is apparent near Thurmont, where the DNR raises catfish, and near Waldorf, where the department raises sunfish, Early said.
Those fish would not be raised otherwise, he said.
On the other hand, trout for rodeos are "skimmed off the top" of the supply at the Powell hatchery, Early said.
The hatchery raises and stocks about 300,000 rainbow trout in "put and take" bodies of water in Washington, Frederick, Carroll, Baltimore, Howard, Montgomery, Cecil and other Maryland counties each year.
Moore said the hatchery gives an average of 6,000 to 7,000 trout a year to community groups for their rodeos. Some fish even reach urban areas, such as the city of Baltimore's Patterson Park.
Asked if trout rodeos would be salvaged because they don't require additional work at the Powell hatchery, Early said they would not - the rodeo supply program as a whole is being cut.
Early also said it makes more sense to teach children to fish through an educational program than to let them fend for themselves at rodeos.
The DNR is publicizing a comprehensive annual program it offers called "Hooked on Fishing, Not on Drugs." The program runs most of July and the beginning of August, one week at a time.
"Fishing is more than just going out and catching fish," said Donna Fahres, an angler education coordinator in the DNR's Watershed Services division.
Nonetheless, just catching fish is a thrill, said Ray Grove, a Boonsboro councilman who coordinates a rodeo for the town.
"I think it means a lot," he said. "We have a lot of kids coming up and saying, 'Thanks.'"
Of course, some say that only after their parents prod them, but some do it on their own, he said.
Next week, Boonsboro will have its 11th rodeo.
Children 1 to 12 years of age will be eligible. Every child will pick out a prize on his or her own, Grove said.
To satisfy the roughly 200 young anglers, the town will get 400 to 500 trout from the hatchery. The park will get crowded.
In an interview for a feature story last winter, Moore said that one of the joys of his job is seeing a child reel in his first fish at a rodeo. On his desk, he keeps a photo of a grinning boy who's posing with two fish.
"We have kids up here that's never fished," said Larry Stouffer, the membership secretary for the Washington County chapter of the Izaak Walton League of America, a national conservation organization.
The chapter's rodeos have been going on west of Hagerstown for "years and years and years," Stouffer said - too long for him to remember a time when there were none.
Even without advertisements, word gets around; maybe 300 or 400 children show up. They get free theater tickets and other prizes, then they go fish.
Late Saturday morning, David Drawbaugh, 60, of Williamsport, reeled in a fifth fish - the day's limit - for his 4-year-old granddaughter, Samantha Baker. He couldn't convince her to give him a high five or to hold the fish for a picture; she was too worried about getting messy.
"I think if young kids are going to become outdoorspeople ... you've got to start somewhere," Drawbaugh said.
Samantha, a rookie around fish, pointed to the one still moving in her bag. "This one does tricks," she said.