Larry,
I dug around in both Scott's and Taggart's AAR's through their divisional histories and even my 30th regimental history... yet not one word about the bridge or ever going to Heidelburg. According to the maps showing their axis of advance, Heidelburg was WAY outside of it. WAY south of their line of advance by, I'd guess 20 to 40 miles... something like that.
The 3rd advanced across the Rhine at Worms, Germany, on the 15th of March, and arrived at Worth, Germany on the evening of the 29th advancing through Heppenheim.
The 3rd at the time was assigned to the XV Corps. 6th Army Group. They moved in the direction of Wurzburg, Germany. VI Corps. containing the 14th Armored, 36th ID and 70th ID... moved through the Heidelburg area around the 29th of March. The 3rd was with the VI Corps. for the majority of the war but, not at the time of the Rhine Crossing and their drive into Germany.
Regards,
MARNE