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Mariners Grand Slam History

Grand Slam Camps first summer camps were held in 1993. Created by a married couple, Mark and Sue Zender, as an improvement to the summer sports camps available.  Mark and Sue wanted to create a camp that had all the fun and memories of real childhood  summer camps, with outstanding instruction from coaches who had achieved at high levels and were great role models. Both having been very active youth athletes and also being dedicated parents of three sports-minded children they knew they could make a better camp!

Mark brought to the camps his teaching, high school coaching and college baseball experience; as well as his being born into a "baseball" family. His father and 8 uncles
all played on a semi-professional baseball team (The Deming Loggers) that took




"Second generation Grand Slam Campers are now showing up on our roster as former campers sign up their children; wishing for them the same great Grand Slam memories they had as a child!"

second place one year in the world series of Semi-Pro baseball. Sue's active youth volunteerism, including years dedicated to daily classroom and PTA activities coupled with care and compassion from working in the healthcare industry,  made her the behind the scenes check and balance, organizer, and mom-point-of-view part of Grand Slam. With this combination of experience and interests a true "Mom and Pop" sports camp was born!

​The first year of camps included locations only in King County.  Over the twenty plus years the focus has been on being the best baseball / softball camp out there. We have survived a number of economic ups and downs, added new locations to meet the demand and have tried to stay current, relevant and provide what parents and campers expect from a camp. We currently have camps located in King, Pierce,Kitsap and Thurston County.​

​We are very proud of our coaches. They are all college or former college ballplayers, enjoy kids and provide excellent role models. Each camp is also coordinated and lead by certified teachers who have played college ball and also coach.  We also have had several coaches who attended Grand Slam Camp as young campers!! Second generationGrand Slam Campers are now starting to show up on our roster as former campers sign up their kids, wishing for them the same great Grand Slam memories they had as a child!