He smiles when I ask about Easter Sunday.
"Easter's pretty ordinary around here. Maybe some people from the churches will come down. But other than that, it's nothing big. We save Thanksgiving and Christmas for our big doings."
"Do you ever get discouraged?" I ask.
Wheeler smiles wearily.
"The majority are very grateful for any help you give," Wheeler says. "Unfortunately, a small percentage ruins it for the majority.
"I've had some sad experiences. I've worked with so many alcoholics and substance abusers over the years."
"You think they're really on their way. Then they hit bottom again. Then I stop and think. I realize it could be me. So you go right on trying to help."
"Did you ever have a drinking problem?" I ask.
"No, I've never smoked or drank. I understand it's not easy. We just don't know what problems people have a lot of times. Some of them will succeed in getting back on their feet. We want to help them. But we have some people here who wouldn't show up for their paycheck on Friday if that was the only thing they were required to do.
"Our guests in the camp think I'm a stern, unbending man. I want them to think that. In some ways, I am. I won't put up with a con. I'd throw my own brother out of this camp if he broke the rules."
"How safe is it to live here?" I ask.
"It's as safe as almost anyplace," Wheeler says. "Don't forget we have such large numbers. There are almost 300 in the tents alone. They are people with problems. The tension level varies with each person.
"Some have pride in themselves. They shower. They clean up. They shave. Others, we have to take them and order them into the shower.
"They can stay here 35 days, but they must work steadily with a counselor who helps them try to get a job. That's not easy. These people--most of them-- don't have cars. You are severely handicapped here if you don't have a car. "We hand out bus passes. Some have bikes. But it just isn't easy to find a job these days."
Wheeler has worked with the homeless for three decades, both in the Midwest and now in Arizona. He has seen a big change.
"The homeless individual is now younger. They used to be in their forties and fifties. Now we see them in their twenties. We see young families with babies and toddlers. We are seeing more young families all the time.
"It will get worse. There are no jobs. The story is always pretty much the same. They came here in their car because there was no work back in Iowa or Michigan or Illinois.
"So the husband and wife and the little kids head out for Arizona. The weather's great. Certainly, they can find a job.
"By the time they get here they're almost broke. Maybe they work for a while. But they work for minimum wage. And once they miss a paycheck, they're broke. After they miss a couple of paychecks, they're on their way down to us."
Wheeler urges me to call Mary Orton, who is the executive director of the center.
Orton directs the overall job of trying to get the homeless back into society.
"People think the homeless are all drunks or crazy people. We have had ex-cops, a former disk jockey. There was even a former Republican state legislator from Delaware here in the camp. There are college graduates and Vietnam veterans and, saddest of all, so many women who are alone. "Try to find work when you don't have 35 cents to get the Republic classifieds. If you have the paper, maybe you don't have the money it takes to get making phone calls."
"There are some stories of great valor. We had a young woman with two small kids. She found a job. But in order to go to work, she had to take her infant child on the bus to a place to stay. Then she had to take another bus and drop off her second child. And she had to be at work by 8 a.m.
"After work, she had to pick them up again by taking buses. She spent eight hours at work and four hours on buses every day.
"The buses aren't predictable. Sometimes this made her late for work. So she got fired from her job.
"We have people here with great skills. Bill Schulz gave us some computers when he quit his campaign for governor. We had no way to set them up. We put a notice on the bulletin board for help.