REVERE – The sign posted on the entrance doors to Wonderland Greyhound Park Thursday summed up the sprawling race track’s demise: “Wonderland Park is closed and has ceased all operations. Thank you for 75 great years.”One hundred track workers, including Lynn and Revere residents, learned they were out of jobs as they showed up for work. Long-time track regulars like James Cook also dropped by Wonderland to hear the bad news.”People thought it was coming. The nail in the coffin was the vote against dog racing,” Cook, a Lynn resident, said.A voter-imposed ban on dog racing went into effect Jan. 1, 2010, forcing Wonderland and Raynham Park, also a former dog track, to scale back operations to feature only wagering on races simulcast from other racetracks.”Things were very bleak when the referendum won,” said state Rep. Kathi-Anne Reinstein, who went to Wonderland to speak to workers, including track employees seeing 30-plus years coming to an end.”I was hugging people, telling them how bad I feel,” she said.Reinstein, a former Wonderland employee, said lawmakers who supported racetrack slot machine legalization hoped to save jobs and expand workforces at gambling venues.Expanded gambling talks on Beacon Hill collapsed earlier this month after the Legislature and Gov. Deval Patrick could not agree on a plan to authorize slot machine venues in addition to the casino legalization plans that the House, Senate and Patrick all supported.Suffolk Downs, the horse racing track straddling the Revere-East Boston line, still has an option to purchase Wonderland and Suffolk assumed a $10 million mortgage held by Wonderland in March.”If Suffolk and Wonderland can combine something could be done down the road. But with development at a standstill, it (Wonderland) will probably remain empty for a few years,” Reinstein said.Cook’s wagering at Wonderland spans more than three decades. As a kid, he got into the track with friends using a phony identification. He remembers when 12,000 people converged on Wonderland for big races and savors the memory of the 1985 race that netted him $13,000.Track managers held out a glimmer of hope to Wonderland employees Thursday, informing them that if expanded gambling ends up being authorized in Massachusetts and if nearby Suffolk Downs wins an expanded gambling license, Wonderland workers would be given preference for jobs.”This is an emotional day for all of us, and the most difficult part of it is the hardworking people who have been given notice that they no longer have a job,” Wonderland President Richard Dalton said in a statement Thursday, adding, “Until the early 1990s when the Connecticut casinos opened, Wonderland was considered the premier greyhound track in the world.”Wonderland officials are under pressure from state racing industry regulators to explain allegations that they have not made payments to Plainridge Racecourse and a regional horsemen’s group.State regulators said they believed Wonderland owed $40,000 to Plainridge and looked forward to an explanation from Wonderland at a meeting scheduled for Sept. 8.