Do all rivers have fish? or have them at one stage?

there's a river at the end of my field and at one part it's about 2-3 meters wide and at the end of my field its just a bit wider than a meter its about 1 feet deep and has a good pile of 2 feet waterfalls an i'm just wondering is there fish in it? the river it leads too has plenty of trout. my dad says though the smaller river i w as talking about does not have fish but wha would he know anyway? @_@