Crossing the river

Rating: 9/10 (26 March 2019)

Something arising from this film which readers may be able to answer.
It's well documented how Chris was totally unprepared for this trip and when he tried to find his way back to civilisation towards the end of July, the river was in full flow and couldn't be crossed. However, he was criticised also for not having a map with him, when, had he been in possession of one, he could have discovered there was a river crossing less than a mile away.
However, I've been reading about the hundreds of attempts by hikers to reach the McCandless bus since 1992 and how many of them have failed to cross the river; indeed, there have been some fatalities attempting to do so.
My question is, the "modern day" explorers would surely have done their homework and know about the existence of the bridge a short way up the river. In the articles I have been reading over the last couple of days, why haven't people attempted to use it to cross safely? Is it no longer there?