No law says that you have to have turkey on Thanksgiving, but just try to imagine the holiday without it.

The Jackson family from Denver doesn't have to imagine.

"Last year, we had pork chops because that's the only thing we had," Tina Jackson said.

The family of five has struggled ever since Tina Jackson's husband, Ken Jackson, was laid off from his shipping and receiving job a few months ago. This year, they asked their church for help.

The Jacksons' church and other community organizations that typically have been a refuge for families down on their luck during the holidays are struggling too.

With less than a week before Thanksgiving, today the Association of Gospel Rescue Missions surveyed 25 of its members in some of the country's biggest cities.

The association found that more than half of those missions -- including ones in Los Angeles, Chicago, Houston, Dallas, Phoenix, Detroit and Seattle -- have seen a "major drop" in turkey donations this year.

The missions "will not be able to provide food boxes the way they have done in the past unless there is a sudden increase in turkey donations in the next couple of days," association president John Ashmen told ABC News.

There is turkey trouble. Charities and food banks nationwide also report donations have plummeted.

Empty Freezers

On a busy downtown street in Denver, Scott Croft and a team of volunteers from the Denver Rescue Mission have been eagerly standing by, waiting for the seasonal stream of drivers who usually pull over this time of year to unload thousands of donated frozen turkeys.

"We've gotten kind of a slow start," said Croft, pacing the side of the road wearing a bright yellow safety vest.

This year, they've done a lot of waiting.

"We started our turkey drive on Nov. 1," said Greta Walker from the Denver Rescue Mission. "Our goal was to get at least 6,000 turkeys. We realized on Nov. 10 that we had zero turkeys in our freezer."

The struggle in Denver is playing out in towns across the country.

In Bridgeport, Conn., charities have met only half of their goal and are still 1,000 turkeys short.

Down south in Atlanta, big corporate donors haven't come back. Donations are down 38 percent.

Out West in Cabazon, Calif., charities have launched a backup plan. They're giving out 10-pound chickens.

Down the road in Compton, Calif., the Salvation Army has 500 requests for turkeys, but all that sits in its ice cold freezer is one lone turkey.

"People just keep applying, and because we don't have the food that we can supply we have to turn them down," said Capt. Ezekiel Guevara of Compton's Salvation Army.

Patricia Torres, a single mom of two, was one of them.

"We take it day by day, you know...I just keep going out looking for a job and you know... my kids they ask me for so much stuff ...I tell them,'ok, later,'" Torres said.

Higher Turkey Prices

Charities blame their empty freezers on the poor economy and higher turkey prices.

"Retail prices will be up, on average, about 20 percent this year," said Thomas Elam of Indiana-based FarmEcon, an agricultural industry consulting firm.

Elam blamed rising costs on a reduction in turkey supply and production this year, along with a steep jump in the price of corn and soybeans farmers feed growing birds. Now, higher prices at the supermarket may be causing fewer people to buy an extra turkey to donate.

"You're not going to see the kind of deep, deep discounts and widespread discounts that we had last year," Elam told ABC News.

ABC News called the CEO of Butterball, Keith Shoemaker, to see if they could help. The company gives away thousands of turkeys every year, but now inventory is way down.

"I just don't have a lot of turkeys sitting anywhere in a bag to give someone at this point," Shoemaker said.

Shoemaker says the company has given away roughly twice the amount of turkey this year as usual, and he says requests for more donations are up.

"You really hate to say no," said Shoemaker. "So we usually don't say no. We may not give them everything they want, but we always want to try to help someone."

So far, Butterball has donated more than 50,000 pounds of turkey this holiday season and about 250,000 pounds throughout the rest of the year.

"It's terrible to see fellow Americans in a desperate situation wanting something to eat. That's not how this country is supposed to work," Shoemaker said.

Closing The Turkey Gap

With no turkey sales in sight, single mom Sylvia McClain realizes she's one of the lucky ones to get a turkey donated to her this year. She's willing to share with a family that didn't.

"It'd be like a sad Thanksgiving," McClain said. "Everybody desires a turkey, and if you don't get one here, you pray to go somewhere else to sign up for a turkey."

Back in Denver, the effort to get the word out helped the city not only to close the so-called turkey gap, but exceed it. The Denver Rescue mission now has collected nearly 11,000 turkeys.

For the Jackson family, that meant church pastor Larry Herron could make a happy delivery.

"Happy Thanksgiving!" the pastor said as he walked through the door.

"It's going to be a blessed Thanksgiving for us," Ken Jackson said. "You can look around the house and see the smiles on their faces. So, it's just wonderful."

Wonderful indeed, and a lot better than pork chops.

How You Can Help

Association of Gospel Rescue Missions: Throughout the nation, various mission of the AGRM are in need of turkeys. Click here to find a mission in your area.

Bridgeport Rescue Mission: To donate turkeys to the Bridgeport Rescue Mission in Connecticut, click here. You can also call them at 203-333-4087. They still need 500 turkeys for the Thanksgiving holiday.

Compton : To donate turkeys to the Compton Salvation Army, click here. You can also call them 310-639-0362 (press 0 for the operator). They still need 150 turkeys for the Thanksgiving holiday.

Hosea Feed the Hungry and Homeless: To donate to any Thanksgiving goods to the Hosea Feed the Hungry and Homeless organization in Atlanta, click here. You can also call them at 404-755-3353. They are especially in need of turkeys for the upcoming holiday.

Denver Rescue Mission: To donate to the Denver Rescue Mission, click here. The mission divides its donations and gives them to smaller charities throughout Denver.

Feeding America: It has a food bank locator that allows you to enter your zip code and find the nearest food bank to drop off food. You also can donate to Feeding America online and request that your donation be used towards Thanksgiving.

Salvation Army: Throughout the nation, various branches of the Salvation Army are in need of turkeys. Click here to find the Salvation Army closest to you.

Volunteers of America: Local chapters of the organization have organized turkey drives and are hosting Thanksgiving meals for those in need. Find your local chapter by clicking here or donate money that can go to Thanksgiving meals.