On Friday, one of the West Coast's top annual events gets underway as Mercer Island High School hosts the eleventh Annual Northwest Invitational just outside of Seattle. A total of 18 teams are set to participate in this year's tournament, including top boys' lacrosse programs from Washington, Oregon, Nevada, Montana and British Columbia, Canada. The action – which continues through Sunday – features an entire slate of teams coming off state or provincial playoff appearances in 2015, including three state championship squads.

Former Mercer Island head coach Ian O'Hearn was an integral figure in getting the event established. O'Hearn believed the establishment of an invitational would play a key role in promoting inter-regional play and also draw teams from outside of the region to participate in a showcase of elite lacrosse. So far, the tournament has already grown from five to 18 teams in just eleven years, making it one of the top high school tournaments in the west.

"The invitational has grown every year, and now we're up to 18 teams," said O'Hearn, who just stepped down after his fourteenth season as the head coach at Mercer Island. "While it's a great cultural experience for a number of teams to come out here, it's also about the competition. A lot of western teams now realize how important it is to travel to other parts of the country in order to face some of the nation's toughest opponents."

In this year's showcase, featured participants include host school Mercer Island and fellow Washington rivals Bainbridge, Bellevue, Eastlake, Issaquah, Skyline, Tahoma & Woodinville, plus Oregon elites Lakeridge, Portland Jesuit, Lincoln and Sunset. Meanwhile, Centennial, Coronado, Faith Lutheran and defending state champ Palo Verde are all traveling from Nevada to participate. Additional schools include the Claremont School and New Westminster Secondary from British Columbia and Hellgate from Montana.

"We like to match up teams to get some diversity among the competition and ensure quality lacrosse," said O'Hearn, whose led Mercer Island to the state title game in 11 of the last 14 seasons. "It's really fun to watch these teams interact, too. They all have a connection of lacrosse, but they're all different people. Plus, the styles of play are often different as well."

In Friday action, arguably the top match-up of the day features Bellevue taking on the Claremont School. Bellevue is already making its claim as a title contender in '16 after storming out to a 3-0 record in the early going. The Wolverines – who captured the '14 Washington Division I championship – are one of the state's most balanced teams this year and will look to preseason All-American attackman Jojo Bethke for production against a talented Claremont squad.

Meanwhile, another premium Friday contest pits Issaquah against Lakeridge, two semifinalists from a year ago in their respective states. Issaquah returns two 15+ goal scorers from a season ago in Jake Lindahl and Jake Gonzalez.

On Saturday, Oregon state quarterfinalist Lincoln takes on defending Washington champion Mercer Island in what shapes up to be an excellent battle between a pair of evenly matched teams. Headed by Ben Berejka & Ezra Tillinger, Mercer Island is equipped with one of the top defensive units in the entire region. Finally, on Sunday, it's a showdown between Tahoma and Sunset to cap tournament play. Expect another exciting contest to finish off play in the '16 Invitational.

With 18 renowned programs from the Western Region slated to play this year, O'Hearn is delighted to see where the invitational has come in the past eleven years. However, for the former Mercer Island coach, it's only the beginning.

"Ultimately, the goal is to get some marquee teams from the East Coast to take part in the invitational and always upgrade the quality of competition," O'Hearn said. "Like the Jesuit Classic has been for the East Coast, we'd like to be the go-to event on the West Coast, and I think we're getting there."

Check out the Northwest Invitational home page

Who: The 2016 Northwest Invitational

What: 18 team interstate high school lacrosse invitational

Where: Mercer Island High School & Islander Middle School

When: Friday, Saturday & Sunday - April 1st-3rd, 2016

Cost: $5 per adult for an all day ticket at the stadium (kids 10 and under are free)