Agents said the canisters, each weighing about 2 pounds, were launched over a border fence by cannon, KTVK-TV, Phoenix, reported Tuesday.
Officials estimate the 33 containers of marijuana found near Yuma Friday were worth more than $40,000.
"You know, as we continue to tighten the border more and more, they'll find every method they can explore to get their drug loads over," Border Patrol Agent K. Linwood Estes told KTVK.
The smugglers crossed the Colorado River with the pneumatic cannon and entered an area of U.S. territory beyond the fence, officials told the Yuma Sun. The smugglers used a carbon dioxide canister to propel the marijuana into a field.
Estes said someone was most likely waiting to collect the marijuana, but couldn't after authorities responded to a call made by a concerned citizen.
While a similar method has been used in California, Estes said "in this area I think this is new" in part because of heightened border security in the Yuma sector.