Hello you will find muskies all the way up the st john river,at least f'ton up.It's good pickerel and bass fishing as well around that area.The Eel river(Dumps into the st.john) is very close to there and is good for both pickerel and bass
I Think the lake you are referring to is Skiff Lake. There's landlocked Salmon, Trout and Bass in this lake. Nearby is 1st Eel Lkae, This has Bass and Pickerel, which was mentionedon another reply . There are also several others such as North Lake, which is on the US Border. Landlocks in that one, but I've only fished the first two,
The muskie's came down the Saint John River so they are definatly in the headpond with Fredericton being the lowest section of the rievr where they can be reliably caught (so far), Woodstock area is good as well. I haven't fished around Canterbury much but Skiff lake has landlocks and I would think that most streams in that area would hold some trout. Grand lake (the one on the border) has most species in it, lake trout, LLS etc.