The days of just going over the boarder are looooong gone !
My grandfather had a house just east of the big Coliseum on Paisano - we were almost at the end of the block, behind us was a ball field and just south of that, the river (usually, just a creek most times of the year). When we'd visit, we'd go over to the Delta Recreation building and play out back, in and across the river, without any hassle at all.
One time, one of the neighbor kids twisted his ankle really bad on the Mexican side of the border. A couple of Juarez city cops were sitting in their Jeep, came over to see what had happened, and stuck the kid in the jeep and just drove him back across the border to his house next door to Grandpa's. No hassle - no international incidents. Just a "thanks for taking care of the boy!"
Yep, those days (50's and 60's) were most definitely different than now.