The places I go often end up with things like that - big snowfields (generally fine)
or things like snow bridges over river - f'rinstance here - brazeau river coming out of nigel pass (in early july!) - and that's a pretty big river:



to put the amount of water to scale, here I am standing in the middle of it at a crossable spot in the pass a kilometer above that spot:




While these things can be safe to cross, they can also kill you very very quickly. What you're talking about are skills tantamount to what you need for glacier travel - which, like mountaineering, can be done relatively safely by the trained and experienced with the right gear. Having said that, doing so without experienced help and gear (like glacier travel) is extermely dangerous. I don't consider myself qualified or fit enough for it, and I don't try it.