I grew up in the area, yes you will need blackfoot licenses.
Not bad fishing there, just if you are going to purchase blackfoot licenses and drive all that way there are better lakes to fish with more and larger trout, although Swift dam has some of the best views of any lake.
Additionally, the wind blows very frequently at Swift dam, and the road in is not plowed/maintained and frequently drifts in. It is a true 4x4 road and sometimes would require a tractor to get in.
If you have further questions, pm me.
