Summer camp for billionaires is back in session as media and technology barons were out in force at the Allen & Co. conference in Sun Valley, Idaho, on Wednesday.

UTA chairman Jim Berkus and IAC/InterActiveCorp chairman Barry Diller biked through the resort’s mall area despite signs asking guests to stick to walking, not wheels.

Google executive chairman Eric Schmidt and Resolution founder Jeff Berg chatted amiably while leaving one of the morning sessions.

Wences Casares, CEO of Bitcoin startup Xapo, searched for a bar or restaurant in which to watch the World Cup match between his native Argentina and the Netherlands.

Twenty-first Century Fox chairman Rupert Murdoch made it a family affair, walking into the conference flanked by sons Lachlan and James.

And Discovery CEO David Zaslav and his wife, Pam, walked hand in hand past the media cadre, while former New York City Mayor Michael Bloomberg made a sort of swatting gesture at the assembled press.

Other guests glimpsed in and around the exclusive confab were Walt Disney Co. chairman Bob Iger, Amazon CEO Jeff Bezos, ESPN president John Skipper, the Weinstein Co. co-chairman Harvey Weinstein, Facebook CEO Mark Zuckerberg and Apple CEO Tim Cook.

Not seen: drones, despite a Bloomberg report that the event’s security team were looking to the skies in the off-chance any unmanned crafts appeared to photograph or imperil guests.

The outfits screamed vacation. Venture capitalist Peter Thiel sported a crisp white polo shirt, Imagine Entertainment co-founder Brian Grazer showcased camouflage shorts and NBCUniversal vice chairman Ron Meyer expressed his institutional pride with a black “Fast 5” T-shirt, in what appeared to be Portuguese.

It can take work to appear so casual. Alice + Olivia CEO and creative director Stacey Bendet Eisner, resplendent in a silver dress, confessed she changed into three outfits a day, crediting her husband, Eric Eisner, a film producer and son of former Disney chief Eisner, with carrying all her luggage.

Guests listened to presentations by basketball great Phil Jackson and Google’s Larry Page, but the main event will take place on Friday when Secretary of State John Kerry is slated to take the stage.

Part of the appeal of the conference is that it unfolds behind closed doors or, in this case, massive hedges, away from the prying eyes of the press. Reporters, with the exception of the New Yorker’s Ken Auletta and Charlie Rose, are prevented from attending the discussions or crossing hastily assembled barriers. That gives the moguls’ entrances and exits into the conference events the feeling of an informal red carpet, one that features shorts and T-shirts instead of haute couture.