Gannon, who played T20I cricket for the USA last year having qualified through his mother's side of the family, took 38 wickets at 20.92 for Queensland in the 2019-2020 campaign, which was truncated by a round due to the Covid-19 pandemic, and becomes one of the more significant off-season deals.
The cutting of Coulter-Nile, who a year ago was part of Australia's World Cup squad but lost his CA contract in April, had been flagged and he is expected to look for opportunity interstate. In the BBL he plays for the Melbourne Stars.
Tye, like Coulter-Nile, is very much a white-ball specialist and has not played a first-class match since 2018. One of the focuses of Adam Voges, the Western Australia coach, was to rebalance the squad with an eye on Sheffield Shield cricket after a poor second half to last season when they were hit by injuries.
Legspinner Liam O'Connor has earned a contract after taking a five-wicket haul on his Western Australia Shield debut last season while pace bowler Lance Morris has been upgraded to a senior contract.
"We identified at the end of last season that our bowling depth in Shield cricket and our spin stocks needed a boost and we're really pleased with our new additions to the squad," Voges said. "It's exciting to have Cam [Gannon] come across to the West. He had a terrific season in red-ball cricket being the leading wicket taker in Sheffield Shield cricket and will bring experience and leadership to our young bowling group.
"We were strong in the Marsh Cup last year and will be looking to start the season well in 50-over cricket. Our focus, no doubt, will be to improve our Sheffield Shield results, we were disappointing at the back end of last season and will be looking to rectify that this year."
In the women's squad, which won the WNCL title last season, Victoria legspinner Alana King has made the move across the country. Allrounder Heather Graham has switched to Tasmania and New Zealand allrounder Sophie Devine won't be available due to international commitments.
"We are thrilled to have Alana join us from Victoria, she'll bring a wealth of experience to the group having played state cricket for a number of seasons now and provides us with another attacking option with both the bat and ball," head coach Becky Grundy said.
Western Australia men's squad Ashton Agar*, Cameron Bancroft, Jason Behrendorff, Jake Carder, Hilton Cartwright, Sam Fanning (rookie), Cameron Gannon, Cameron Green, Liam Guthrie, Aaron Hardie, Bradley Hope (rookie), Josh Inglis, Matthew Kelly, Mitchell Marsh*, Shaun Marsh, David Moody, Lance Morris, Liam O'Connor, Joel Paris, Josh Philippe, Jhye Richardson*, Corey Rocchiccioli (rookie), D'Arcy Short, Marcus Stoinis, Ashton Turner, Sam Whiteman
Western Australia women's squad Megan Banting, Nicole Bolton, Zoe Britcliffe, Mathilda Carmichael, Piepa Cleary, Sheldyn Cooper, Ashley Day, Amy Edgar, Molly Healy, Alana King, Emma King, Taneale Peschel, Chloe Piparo, Georgia Wyllie