Do Workington have many clubs? Think there's just 1 (Seaton?) in the area but yes Maryport is the real RL playing area up there as well as Whitehaven
Seaton is a village in its own right.
As dkw states only Salterbeck are based in the town and over the last 20 odd years they had only two more I can think off,Westfiled and Derwent Park Rangers (youth age groups.)
Whitehaven have had more success but still only have two clubs actually in the town Hensingham and Kells.
Smith Brothers,Mirehouse,Corckickle have all come and gone as have village teams such as Dearham,St Bees,Brigham(Twinames),Broughton Moor,Dalston (and a host of other Carlisle based clubs who went into the CARLA divisions) Aspatria and Penrith of the top of my head.
Still the traditional well established clubs like Kells,Wath Brow,Egremont,Broughton,Maryport.Glasson and Hensingham have (and still are) producing top class amateur players that if they had a higher level of local proffesional teams to look to would not be moving out of the county.
I would say the last real succesful "local pro" side was the town team of the late seventies

who held their own in the top flight for four or five years and boasted 95% local players.
In the 79 Lancashire cup final (fourth in four years) against Widnes (Cup kings at the time) only Harry Beverley and Iain McCourcadale did not come from the local amatuer scene.
1.Charlo (Kells) 2.Corkey (Oldham RU??) 3.Kevin Maughan (Red Rose) 4.Tomo (Red Rose) 5 Becky (Clifton) 6.Chuddy (W.Brow) 7.Boxer (Kells) 8.Bev (Dewsbury) 9.Banksy (Egremont) 10.Gary Wallbanks (Red Rose) 11.Ray Lewis(Hensingham??) 12.Ian Hartley (Egremont) 13.Dobie (Red Rose) 14 Sol (Kells??) 15 Varty (Red Rose)
Maughan,Tomo,Chuddy,Becky,Wallbanks,Lewy,Sol and Hartley would all be under 22 at the time.
Its hard to see that type of local representation taking either Town or Haven to higher levels in the future.