Upvote:6
As far as I'm aware there is no rule that allows non-Mexico citizens from entering the border zone without an I-94 permit.
Mexico citizens can cross into the border zone with just a Border Crossing Card (BCC) with no passport and no I-94, as long as they are to remain in the border zone and then crossing back into Mexico. The border zone is approx 25 miles, however some crossings allow further (for eg 55 miles into New Mexico and 75 miles into Arizona). Source
Non-Mexico citizens* with a B1/B2 visa must hold or obtain a valid I-94 permit when entering the United States from Mexico, even if only entering the border zone. Source: I am a non-citizen Mexico resident and B1/B2 Visa holder that crosses at Otay Mesa and San Ysidro into San Diego regularly (several times a month).
* Excluding US and Canada Citizens - US Citizens obviously don't need any of the above to enter the US, and Canada Citizens don't require a Visa or an I-94 permit to enter.