As comprehensive immigration reform winds its way through Congress, The Center for Investigative Reporting is releasing findings from our deep look into which drugs are crossing the 2,000-mile border that separates the United States from Mexico.

We analyzed the 128,169 seizures made from January 2005 to early October 2011 by the U.S. Border Patrol at checkpoints and other spots near the border and by U.S. Customs and Border Protection at ports of entry.

We found:

(Note: We know you’re noticing these add up to more than 128,169 seizures. Some seizures involved more than one type of drug.)

If you poke through the map you’ll notice that each drug has its own interesting storylines of geography and development over time, but there were two obvious standout stories: stations with lots of big marijuana busts, and stations with lots of very small marijuana busts.

Lots of big marijuana busts

Here are the Border Patrol stations with large marijuana seizures (notice they’re mostly in Arizona): 

StationMarijuana seizuresWeight seized
(in pounds)
Median weight seized
(in pounds)
Nogales Station, Ariz.6,8641,464,390144.7
Ajo Station, Ariz.3,5101,294,258277.0
Tucson Station, Ariz.3,442805,021194.6
Casa Grande Station, Ariz.3,1951,019,125246.2
Sonoita Station, Ariz.2,665762,293251.8
Rio Grande City Station, Texas1,706976,627421.6
Naco Station, Ariz.1,310198,149109.5
Lordsburg Station, N.M.1,256264,152197.8
Laredo South Station, Texas835174,928163.7
Eagle Pass Station, Texas632128,421164.0

Lots of little marijuana busts

Here are the Border Patrol stations with many small marijuana seizures: 

StationMarijuana seizuresWeight seized (in pounds)Median weight seized (in ounces)
Wellton Station, Ariz.8,938126,1240.14
Sierra Blanca Station, Texas5,076163,3860.72
Yuma Station, Ariz.2,571141,7250.3
Campo Station, Calif.1,506111,1780.45
Alamogordo Station, N.M.1,02440,5990.64
Blythe Station, Calif.7538,0290.2
San Clemente Station, Calif.59124,1340.27

So where did this data come from?

Using internal data released by U.S. Customs and Border Protection through Freedom of Information Act requests, CIR’s news applications developer, Michael Corey, created an interactive map and data API to show the amount of drugs seized by the U.S. Border Patrol and at ports of entry between January 2005 and early October 2011.

We wanted a detailed geographic breakdown of drug seizures along the border, but the agency’s first response was limited to seizure totals aggregated over large areas – not useful for our purposes. We wanted data on each bust, so we appealed.

Four months or so later, we received more than 80,000 rows of data on individual drug busts made by the U.S. Border Patrol, which often operates in remote areas inside the United States between formal border crossings.

For each Border Patrol seizure, we have information on how much of each drug was seized and which Border Patrol station was responsible, along with the citizenship status of anyone detained. Read our story here about citizenship.

We also got additional data (nearly 50,000 rows) with more limited geographical information from the folks who oversee the nation’s ports of entry, Customs and Border Protection’s Office of Field Operations. 

So now that you know how we crunched the numbers, check out our interactive map of drug seizures along the U.S.-Mexico border. Tweet us at @CIRonline or post below in comments about what kind of trends or patterns you’re seeing in the data.

For more homeland and national security coverage, visit Crossing the Line and follow reporters Andrew Becker at @ABeckerCIR and G.W. Schulz at @GWSchulzCIR.

Kelly Chen is a news engagement specialist at The Center for Investigative Reporting. She manages the day-to-day social media strategies and online engagement for CIR. In addition, she works to break down complex issues and ideas and create content for CIR's online communities. Kelly also works to increase engagement on cironline.org and on other online platforms. Previously, she produced discussion segments for PBS NewsHour and oversaw social media and engagement efforts for the American Graduate project, a public media initiative on the high school dropout crisis. She's also worked at Southern California Public Radio and National Geographic TV. A native of Los Angeles, she studied international relations and English at UC Davis.