The end of a presidential press conference was once the beginning of a stampede -- a herd of intense journalists rushing and elbowing their way to the nearest phones.

But President Reagan's encounter with reporters Tuesday night ended more with the whimpers of journalists ambling back to their editors to argue that they had no story.

"I walked out of there with a mandate to do a minute-and-45-second piece, and usually I'm trying to figure out how to get it all in. Last night, I was in a panic," said CBS White House correspondent Lesley Stahl yesterday. "What would I use as news?"

Los Angeles Times Bureau Chief Jack Nelson said he and his news editors looked at each other after the press conference and realized that "for the first time after one of these things, we didn't have a lead. It was a throwaway."

Said Sam Donaldson of ABC: "It was an awful press conference from the standpoint of delivering information."

Stahl keyed her report to Reagan's opening statement, as did The New York Times, which used a front page story. The Los Angeles Times' coverage consisted of a new lead paragraph on an inside page story.

With some of the nation's best journalists sitting in front of the president and asking him questions, why did so few answers qualify as news?

Some journalists said the allotted half-hour was devoured by Reagan's opening statement (in this case on how his budget cut only "unessential items"), by the president's suggestions that he could not comment on a variety of matters and by questions from "nonestablishment journalists," as one establishment journalist put it.

For example, one question went to Evelyn Y. Davis, best known for her appearances at various stockholder meetings where she has, on occasion, loudly needled corporate officials about policies she finds objectionable.

Davis caught the president's eye, and he said, "I'm going to call on you, not because you've got a red dress on, but just because you caught my eye," referring to his reputation for calling on reporters wearing Mrs. Reagan's favorite color.

Davis, who also noted that her dress was by "Nancy's favorite designer," then asked whether the president would consider legislation to limit corporate mergers -- a query that brought a polite brushoff from the commander in chief.

From there, Reagan had apparently planned to let Baltimore Sun White House reporter Robert R. Timberg have a question, but Timberg was preempted by Lester Kinsolving, listed at the White House as working for Globe Syndicate.

"Lester just took it, he just took it," said an irritated Timberg. "He clearly has no compunction to ride roughshod over his colleagues."

Kinsolving, who was wearing a red sports jacket, bellowed about the "injustice" of Reagan giving an exclusive interview to The Washington Post this week when the president has complained about Herblock's cartoons showing Secretary of Defense Caspar Weinberger with a toilet seat around his neck.

Defending his right to give exclusive interviews, Reagan laughed and compared the cost of a $600 toilet cover with the one on commercial airlines -- a comparison that brought laughter from reporters.

Some reporters suspect that Reagan uses such questions to get the mainstream journalists off the track. "It may be that he deliberately tries to get a question that is not in the normal flow of news," said Stahl.

But the entire event had many veteran White House correspondents -- generally a frustrated lot -- -unusually frustrated.

"I'm not ready to join Mr. Sidey [Time columnist Hugh Sidey] to say that we should abolish the presidential press conference because of the need for keeping the tradition for Reagan's successor," said a dispirited Donaldson. "But the process of trying to get information from Ronald Reagan himself has now broken down to such an extent that it is a demoralizing experience."

folo10fKeep an Eye Out for SpyFor some time now, Life writer E. Graydon Carter and Time architecture critic Kurt Andersen have been among the ranks of those yearning for an irreverent publication on the order of Britain's naughty Private Eye or "The New Yorker as it was during its first 10 years . . . the real New Yorker, when it was talkier and funnier," as Andersen puts it.

Finally, investment banker Tom Phillips agreed to try to raise $1.25 million to help start what will be called Spy and is optimistically scheduled to be on the stands (at $2.25 per copy) this fall.

Andersen said that Spy writers will try to be a counterpoint to "the inexecrable tide of blandness" that has besieged the magazine business. The antidote should be "something of the David Letterman show sensibility."

"We've got a new term for it, 'literate sensationalism,' " Andersen said. "It's a shame that only the tabloids of the world get to have the fun of sensationalism." Going in for the Keillor

Almost nobody famous in modern America has been treated as reverently as Garrison Keillor, creator and commentator of the delightfully real world of the mythical Lake Wobegon. "The little town that time forgot," as he describes Wobegon in his Saturday night radio show "A Prairie Home Companion," was in fact remembered fondly by Time in November with a valentine of a cover story.

People magazine has been kind. Columnist James J. Kilpatrick offered a recent endorsement for Keillor's new book that was so effusive it must have embarrassed Keillor's press agent.

But if Keillor is the mascot of the national media, home-town journalists have not been so neighborly, at least by Keillor's tough standards of neighborliness.

Many a Minnesota newsman believes that Keillor's new pet -- "Rick the TV Dog" -- is the canine version of his least favorite journalist, Nick Coleman. Rick is described as a mangy Irish setter that goes out and rummages through the garbage and then crawls into bed and stinks up the sheets.

Coleman, an Irishman who is television critic for the Minneapolis Star and Tribune, denies any such behavior but acknowledges that he has found himself in the uncomfortable position of chipping away at Keillor's halo. It has won him few friends among Keillor's audience. Minnesota Public Radio officials have cut him from their mailing list. Employes have been told not to answer his phone calls.

And especially woeful is Keillor himself.

Coleman said that the "unfortunate" feud seemed to begin after Keillor went on the David Letterman television show a few years ago and recited Minnesota's counties in alphabetical order. Coleman, who describes himself as "the only other person who would know or care," wrote a column chastising Keillor for omitting three counties.

"He was very upset, and it took me by surprise," Coleman said. "After that, he changed the story about why Lake Wobegon was not on the map . . . After that, it was because some drunken Irish surveyor called Coleman had left it off."

Unchastened, Coleman has written more critical columns and broke the news that Keillor was marrying his high school sweetheart, thus ending his relationship with his longtime producer Margaret Moos (who has since left the job).

It was that story that brought the outcry from Wobegon fans and complaints from Minnesota Public Radio to Star and Tribune Executive Editor Joel Kramer. Kramer said Coleman "doesn't create a problem for us" and said the story was a normal part of Coleman's beat, which would continue to be covering television and radio, including Keillor.

Keillor, who gave several interviews to other reporters, was outraged and told one interviewer that he felt as though he had crawled in bed with a mangy dog. Shortly afterwards, Keillor's dog with a nose for garbage appeared on the show.

Minnesota Public Radio Director of Public Relations Cathy deMoll said that only Keillor could say for sure whether Rick, the TV dog, was meant to be Nick, the TV columnist. And Keillor himself was traveling and not available.

"Rick is a dog that sits in somebody's lap and watches TV, and he's actually quite a complex character with some very endearing qualities," said deMoll.

Coleman, who said that he is a loyal Keillor fan, acknowledges that like Rick he spends most of his time watching TV.

"But I don't know," said Coleman. "Maybe I'm reading too much into it."