Communities throughout Southern California begin an ambitious effort starting today – find out how many homeless people live here.
Volunteers will literally go out onto the streets with tally sheets.
They'll count the number of people they see living in vehicles, residing in encampments and more.
The information is combined with data that shelters have on the homeless people they're currently helping, too.
"We have one of the most significant logistical challenges because we're a vast territory," says Peter Lynn of LA Homeless Services Authority, which coordinates the count in Los Angeles county.
Past censuses have revealed that, in many areas, the homeless population has steadily increased in the past several years.
But it takes a certain amount of ingenuity to learn this.
Some homeless people are hidden and don't want to be found.
"Homeless youth are particularly challenging to count during the street census," says Lynn. "Data have shown that they avoid the areas where they might be visible."
So one tactic they've used is asking other homeless youths to count each other.
This year, LA County is also taking extra steps to learn whether some homeless people are transgender, have pets that they can't take into shelters, are currently institutionalized and more.
This information will help determine where money, resources and services might be deployed throughout the region.
"That's part of the allocation process," says Lynn. "It's one of the pieces of information we use."
Homeless has become such an important issue in the region that this count, mandated by the federal government to take place every two years, is now funded by LA city and county to be an annual event.
The count in L.A. begins its three-day count today. Riverside County will do a single-night count today, as well. San Bernardino's is Jan. 26. And Orange County's is Jan. 28.