But on the two-year anniversary of Gov. Kim Reynolds signing sports betting into law, Iowa sportsbooks have generated $101.1 million in operator revenue since the industry launched in 2019, giving the state's sports betting industry a historic milestone on its second birthday, according to PlayIA.

"Seeing $100 million in lifetime revenue is an attention-getting milestone that crystallizes just how much growth Iowa has enjoyed this year," said Jessica Welman, analyst for PlayIA.com. "The removal of in-person registration at the beginning of the year has been the catalyst for the industry's expectation-busting start to the year. But other factors have helped, too, including a fierce competition among some of the country's best-known operators, which have been aggressive and creative in reaching new bettors."

Iowa sportsbooks accepted $118.4 million in bets in April, according to official data released Friday. That is down 26.7% from the record $161.4 million in wagers in March and the lowest volume since sportsbooks collected $104.8 million in bets in December.

Net operator revenue was relatively strong though, hitting $7.7 million in April. That was down 42.6% from April's record $13.5 million in net receipts. April's revenue produced $521,455 in state taxes. Since January, when in-person registration rules were lifted, Iowa sportsbooks have produced $40.2 million in net receipts, or 39.8% of the state's lifetime handle.

Without the NFL or the NCAA Tournament, sports betting has historically lightened from April through August in legal U.S. markets.

"Nothing can quite replace the interest that the NFL and the NCAA Tournament drives, so a pullback in April is no surprise," said Dustin Gouker, analyst for PlayIA.com. "But with a full month of regular season NBA and Major League Baseball, Iowa still put together a decent showing in April. That is an excellent sign as we head into the slower summer months, which could be busier than in an ordinary year because of the Olympics and later-than-usual NBA playoffs."

Online betting generated $104.5 million in bets or 88.3% of the state's overall handle. Meanwhile, retail betting fell to $13.8 million from $22.1 million in March.

Longstanding Iowa leader William Hill, which is partners with six Iowa casinos — Prairie Meadows, Horseshoe Casino Council Bluffs, Isle Casino Hotel Waterloo, Isle of Capri Bettendorf, Lakeside, and Harrah's Council Bluffs — topped the market with $39.1 million in handle, including $35.7 million in online wagers. April produced $1.8 million in net receipts.

Wild Rose took in $34.6 million in online and retail bets. That included $34.3 million online. Still, Wild Rose led the market with $2.6 million in net receipts.

FanDuel and BetMGM helped put Diamond Jo in third place with $29.2 million in April bets, which included $26.1 million in online wagering.

"The Iowa market is still a long way from maturity," Welman said. "The largest sportsbooks are in a fight for market share while competitors turn their eyes to Iowa, an increasingly attractive market for emerging operators. The next few months should bring a flurry of activity, as operators jockey for position ahead of football season."