MISSOULA -- Dominic Umile was impressed by the crowd waiting Thursday morning for tickets to U.S. Sen. Barack Obama's Missoula campaign stop.

"There were four, five, six 11 people there," the 3-year-old Missoula boy counted as he spun around a parking meter post.

He'd waited patiently for 40 minutes with his mother and father, Janicka and Marc, while the line snaked through Obama's Front Street office.

The Umiles were some of the last of about 1,500 people who picked up tickets in person for the Democratic presidential candidate's Saturday appearance at the University of Montana's Adams Center.

By 11 a.m. Thursday, those tickets were gone. Another reported 6,000 tickets were snapped up on the Internet by 10 a.m.

"This is an exciting opportunity for Missoula to see these political candidates," Janicka Umile said.

"That's why we're taking our children -- so they can say they saw these people when they came through," she added.

Obama communications director Matt Chandler later said the 7,500 ticket total was incorrect, and would not give a correct number.

He said the national campaign advance staff has a policy of not releasing event numbers.

Adams Center staff said the arena holds 7,700 people for gatherings if spectators stand on the floor as well as the bleachers.

However, they may also open an auxiliary gym if there is an overflow crowd, which could make room for 10,000 people.

Obama's campaign outpost is in the same building as Sen. Max Baucus' new Missoula office, and just over a block away from Rep. Denny Rehberg's office.

The Illinois senator's campaign office opened at 9 a.m. and already had a crowd waiting in the 32-degree sunshine.

Other than the live bodies, the only other things in the office so far were a couple of tables, four computers and two large boxes of clipboards and telephones.

"Our campaign is grass-roots," Chandler said. "We rely on people telling people about Obama for support."

While the tickets were available, campaign workers mingled in the line with clipboards, signing up volunteers for a Friday evening sign-making party and other tasks. However, campaign workers said Thursday evening that plans for the sign-making party were tenative.

As Montana's June 3 presidential primary approaches, the office will also support phone banks, precinct organizers and other get-out-the-vote efforts.

Marc Umile said he started supporting Obama shortly after former senator John Edwards dropped out of the race. His wife, Janicka, remained on the fence. In addition to seeing Obama on Saturday, she said she hoped Sen. Hillary Clinton would add a public event to her Sunday fundraising stop in Missoula.

"I'm a mom with two children, so it's hard to find time to go online and research them," she said. "I still hope to hear what he (Obama) has to say about health care, the economy and the environment. I'll compare that to what Hillary's said and make up my mind."