Lamar and Teresa welcomed strangers into their home.

Located underneath a bridge, their shelter was lit by candles. A box of cereal, instant coffee, potato chips, and other food items were neatly arranged along a sloped dirt and rock wall. A separate "bedroom" holds a mattress, and mats carefully cover the ground.

"The two of us live here," said Lamar, patiently telling the strangers his story. Less than a week until the Super Bowl, both donned San Francisco 49ers apparel.

They were among those being counted during the annual homeless census in Contra Costa County in Northern California. Communities across the country take part in a one-night homeless count each January.

The effort gives local authorities the data they need to better understand the number and characteristics of the homeless population, said Lavonna Martin, acting director of the Contra Costa Health Services homeless program. It's also a factor when receiving federal funding.

This year, volunteers were tasked with collecting more precise age data, the number of homeless children in families, and even the gender of homeless veterans. In an effort to better serve homeless youths, federal authorities changed its data collection requirements for 2013 to better identify homeless children and youths.

The makeshift walls that help hide Lamar and Teresa and their commitment to keep their camp clean make them hard to detect.

A 51-year-old union waterproofer, Lamar was laid off from a job and then broke his ankle.

Teresa, his girlfriend, used to work at drug store, but she also lost her job when the store was acquired by a competing chain.

Now, they rely on unemployment benefits and money they get from recycling cans and bottles.

They are the only two living here, but others drop by regularly to get something to eat or to get warm.

"Not all homeless people are bad," Lamar said more than once.

Just a short walk away, Rory is sleeping out in the open. "It's cold," he told Martin, showing her the several layers of bedding that covered him. The 54-year-old has been in this location in Concord for three weeks.

After some talk about getting him into a shelter, the outreach team bids him farewell.

From the busy road nearby, Lamar, Teresa, and Rory are out of sight. They are easy to miss, but on this morning they were counted.