Department of Public Safety Trooper Gerald Bryant said Tuesday that one of the men's daughters, ages 3 and 5, were in the seats but not buckled up.
The traffic stop, which yielded nearly $650,000 worth of cocaine, happened Saturday in Victoria as the McAllen men headed to Houston.
Arturo Ortiz Jr. was jailed Tuesday on a charge of possession of a controlled substance, with bond at $75,000.
DPS says Christopher Cortez is held without bond for contempt for failure to pay child support, plus he'll face a drug possession charge. His two daughters were released to other relatives.
Online jail records did not list attorneys for the men.
