Keighley Cougars is a professional rugby league club from Keighley in West Yorkshire, England who compete in Kingstone Press League 1, the third tier of English rugby league (behind the Super League and Kingstone Press Championship).
 Their home ground, Cougar Park (originally known as Lawkholme Lane), has an estimated capacity of 7,800.
 Before the 1991–92 season, the club was known simply as Keighley RLFC.
Danny Nicklas is an English rugby league footballer who played for Hull F.C. in the European Super League competition.
 He plays as a stand-off.
 He currently plays for Newcastle Thunder in the Kingstone Press League 1.
 He used to play for the York City Knights and he has also played in the Kingstone Press League 1 for teams Gloucestershire All Golds.
The 2016 League 1, known as the Kingstone Press League 1 for sponsorship reasons, was a semi-professional rugby league football competition played in England, the third tier of the sport in the country.
Mel Mason is an English professional rugby league footballer who played in the 1970s, and 1980s, playing at representative level for Cumbria, and at club level for Featherstone Rovers (Heritage № 500), Leeds, Barrow, and Whitehaven, as a stand-off/five-eighth , i.e. number 6.
Newcastle Thunder R.L.F.C. is a professional rugby league club based in Newcastle upon Tyne, England.
 They play in the Kingstone Press League 1 competition, the third tier of rugby league in the United Kingdom.
 They play their home matches at Kingston Park, also home to rugby union side Newcastle Falcons.
 The club was known as Gateshead Thunder until 2015.
Workington Town R.L.F.C. is a semi-professional rugby league club playing in Workington in west Cumbria.
 In the 2017 season they will play in League 1, having been relegated from the Kingstone Press Championship.
 Their stadium is called the Derwent Park, which they share with Workington Comets, a speedway team.
Hemel Stags R.L.C. is a Semi-professional rugby league club based in Hemel Hempstead, Hertfordshire, England.
 The club has played in Kingstone Press League 1 since the 2013 season.
The 2017 League 1, known as the Kingstone Press League 1 for sponsorship reasons, was a semi-professional rugby league football competition played in England, Wales and Canada, the third tier of the sport for RFL affiliated clubs.
Whitehaven R.L.F.C. is a semi-professional rugby league club playing in Whitehaven in west Cumbria.
 They play in Kingstone Press League 1.
 Their stadium is called the Recreation Ground (known locally as the Recre).
North Wales Crusaders R.L.F.C. (Welsh: "Croesgadwyr Gogledd Cymru Rygbi'r Gynghrair" ) is a professional rugby league club based in Wrexham, Wales.
 They are the successors to the former Super League club Crusaders Rugby League.
 Crusaders compete in Kingstone Press League 1, the third tier of European rugby league (behind the Super League and Kingstone Press Championship).
 Until the end of 2016 they played their home games at the Racecourse Ground in Wrexham.
 From 2017 they are based at the Queensway Stadium (also in Wrexham) but will also play several games at Hare Lane in Chester.

Question: Which semi-professional rugby league club in west Cumbria that play in Kingstone Press League 1 for whom Mel Mason played at club level?
Answer: Whitehaven R.L.F.C.