I-35 northbound begins at a traffic-signaled intersection with Bus. I-35-A in Laredo, Texas, just north of the Rio Grande and the international border between Mexico and the US. It has a concurrency with US 83. Through Webb, La Salle, and Frio counties, it has a mostly north-northeastern course, turning more northeasterly around Moore. It then cuts across the corners of Medina and Atascosa counties before entering Bexar County and San Antonio.
i-35 nOrtHbound BEgiNs At A traffic-sIgNaled inteRsectiON with BUs. i-35-a in laReDo, tEXas, juSt North oF thE RIo GraNdE anD the intErNaTIOnal boRder betWeEn MeXico And the Us. It has a COncUrREncY with uS 83. throUGh webb, La SAlle, aND fRio CounTies, it has a mostly NoRth-nOrTHeasteRN CoUrse, turning mOrE northeaSTERly aroUnD moORe. it Then cUts acrOSs thE cOrnERS Of mEDinA AnD aTascOsa couNtiEs bEfoRe enteRInG bexar county ANd San antoNio.