GREENFIELD — What began as just a few friends playing at the Green River Swimming and Recreation Area has turned into an inter-generational group of ultimate Frisbee players who meet, rain or shine, at the Greenfield Community College fields on a weekly basis.

The group, now referred to as “Greenfield Pickup,” draws in players from multiple states. The youngest player is 12 years old, while the oldest player is a man who’s been at every single game since the beginning.

Terry Plotkin, 69, is one of the original founders of the group, which first played together on Columbus Day 1984. Originally from Orange, Plotkin has lived in Greenfield for 43 years, with his ultimate Frisbee experience beginning in college during his time at the University of Massachusetts in 1976.

Plotkin and his group of friends would play “Frisbee football” outside their dorm, oblivious that the sport would soon be coined as ultimate Frisbee within the next few years. The first official collegiate game was played between Rutgers and Princeton in 1972, however, Plotkin and his friends had no idea. It wasn’t until Plotkin witnessed a large-scale match while driving through Amherst years after graduating that he noticed how quickly the sport was growing. Since then, Plotkin has almost single-handedly transformed the ultimate Frisbee scene in Greenfield.

“We started playing every Thursday night in the fall. We played at the Green River Swimming Area for at least 10 or 15 years,” Plotkin recounted. “We liked it there because we could swim after we played, which was great. We formed a team and it was called ‘GRUFF’ (Green River Ultimate Frisbee).”

The team began competing in the 1980s before Plotkin took things to another level by forming and coaching a middle and high school team at Greenfield Center School, where his son was enrolled. Plotkin then repeated his success at Four Rivers Charter Public School, with the sport’s popularity rising significantly throughout western Massachusetts at the time.

“By 2016 our numbers took off and we were running around 25 or 30 people every time, and we had two full-time games going on one field,” Plotkin said. “I think because we stayed consistent and we played through all weather, we kept it welcoming and spirited. We worked hard at it.”

One of the most notable players that Plotkin has coached was Kai Delorenzo, who went on to play for the Madison Radicals, an ultimate Frisbee team at the University of Wisconsin.

Marc Guillaume, 52, has been a consistent player in the group for seven years. He even co-authored a book with Plotkin called “Ultimate Matters,” which follows a high school team on their journey to success.

Originally from western New York, Guillaume found ultimate Frisbee while working overseas in Africa, where the sport was surprisingly popular. When he moved to Greenfield, he joined Greenfield Pickup and initiated the idea of a weekly email newsletter. Guillaume has now introduced his daughter to the group, where the two play together.

“It’s not a formal league, so it’s maybe even more impressive that an informal group has gotten together every Sunday for 40 years,” Guillaume said. A potluck celebration with a mini tournament was held on Oct. 20 to celebrate the 40th anniversary.

When asked how new players can get involved in Greenfield Pickup, or even just ultimate Frisbee in the area more generally, Guillaume mentioned that the website valleyultimate.org often posts events. Those who are interested can also visit the Greenfield Pickup Facebook page at facebook.com/groups/greenfieldultimate to learn more.

For anyone who’s never tried the sport before, both Plotkin and Guillaume encourage beginners to start with a positive attitude and the enthusiasm to work together with others. Ultimate Frisbee is an extremely collaborative sport due to the fact that whenever you catch a pass, you need to stop moving and rely on your teammates to make it progressively closer to the opposite goal. Guillaume pointed out that this is one of the ways ultimate Frisbee is distinctly different from other team sports such as football, soccer or baseball, where you can technically score all on your own even if you’re surrounded by teammates.

Additionally, the sport’s rules make it so that it’s extremely common for matches to be self-refereed, meaning that players have to follow the honor system when making their own calls for points. Guillaume, who also coaches, described a unique moment referred to as a “spirit circle” in competitions. If the two teams disagree on an outcome of a goal or point, it’s encouraged for them to talk it out.

“It’s incredible when it works because basically the coaches aren’t supposed to do anything,” Guillaume explained. “You stand back, give them five minutes and they figure it out. For students, it can be very empowering. It’s an official rule and there’s a whole system of how you go about the process.”

Greenfield Pickup continues throughout the winter, making it one of the only options for pickup games in the area. With ultimate Frisbee still increasing in popularity, Greenfield Pickup shows no sign of slowing down.