It is a summertime, Thursday night staple in the Portland, OR metro area and to celebrate 50 years of racing Thursday Night Motocross plans to open the throttle and make it a party on, of course, Thursday, at Portland International Raceway.

The 50th anniversary race coincides with Round 9 of the 2016 Lucas Oil Pro Motocross series, also celebrating 50 years of Motocross in the United States, on Saturday in Washougal, WA. Though TNMX started night racing in early the 1970s under its current structure, the track officially opened in 1967 on the weekends under the PIR brand with the first official race hosted in 1966, thus the anniversary race.

TNMX emerged when flat-track racing fan Jim Rockstead approached Duane Wylder, who met the first year of PIR Motocross, about setting up Motocross racing under the lights. Thursday was chosen to avoid competing with weekend venues, give riders something to look forward to during the week and for the availability on PIR's schedule. It's been a landmark ever since. Today, Wylder's sons Rick and Ron Wylder, who took over operations in 2006, carry the legacy forward.

"Ron and I both have careers outside of TNMX so this means the world to us or we wouldn't continue to work as hard as we do with the passion we have," said Rick Wylder. "Our father originally got into this sport, like many dads do, because of Ron and I. One thing led to another and he quickly became involved in the sport from an operational and organizational perspective."

Duane Wylder passed away in October and his sons plan to honor him Thursday with a tribute lap led by them and followed by TNMX sponsored team riders. Additional festivities include a military detail, live music, custom awards and a bunch of giveaways. Rick Wylder said his Dad expressed how proud he was of him and Ron prior to his passing and how much "cooler" TNMX is today because of their commitment.

"'Cool' was kind of his word for all things he wanted to be part of," said Wylder.

TNMX generally begins its racing season in April and weather permitting hosts Motocross races every Thursday through October using a points system to determine a Champion, just like the pro levels. Gates drop for a number of men's and women's racing classes including 50cc for ages 4 through 8 to an Old Timer class for those 40 years and older but the real money is made in the Pro level class. In fact, several times throughout the season the schedule includes a Pro level 300 percent cash payback race but the 50th Anniversary race jacks the purse up to $15,000 including extra surprises.

Pro rider Rory Sullivan, 32, has attended TNMX on and off for about 20 years. He's raced and won in a number of classes starting with the 80cc class as a youngster to the current Pro class. He's planning to attend Thursday in a vintage race that's more for fun.

"It's a unique venue in the fact it's in a city park. People can get off school or work early and go race on a weeknight. It's pretty special," Sullivan said. "It's probably one of the main reasons why we have a few top pros out of the Northwest who have made it to the factory level."

TNMX sponsors its own team of riders, chosen by Rick and Ron, who compete but racing at TNMX is open to anyone who rides. All that's required is a helmet, riding boots, gloves, goggles and Motocross style riding pants. Chuck Sun, of Sherwood, OR, raced at TNMX before he won the 1980 500cc class Motocross Championship as did Rick Burgett who won the 1978 title in the same class.

Current riders who have taken a lap or two around the track include Weston Peick who raced there three years ago, Josh Hill who is from Oregon, and Ben LaMay, among others. Pros often attend and even race TNMX events and Wylder said he's hopeful some turn out on Thursday but the track does not have pre-race sign-up so it's always a surprise who shows up.

"We've purposely supported that strategy because our dad always said if you build a good track, have good people supporting the track, make it competitive and fun, everyone will want to race and the fans will want to watch," Wylder said. "We've heard rumors it'll be our largest field to date and we've taken calls from some seriously talented riders that support the rumor."

Wylder certainly holds an impressive memory of races over the years but a standout includes the one Peick entered because he started last, worked his way to the front, won by 50 feet and celebrated with an "old school" Motocross move after crossing the checkers. Another gem occurred off the track when fans and riders donated the single largest cash donation to the Cancer Tumor Research Bank in 2014.

Operating a track in a major metropolitan area does not come without some hiccups, or perhaps more pointedly, whoops. TNMX is located just south of the Oregon/Washington border along a highly congested stretch of the 5 freeway especially northbound during the afternoon hour but it's also as Wylder said "down the street" from riders in Portland and Vancouver, WA.

"Our facility is clean. We have always catered to the grassroots-family environment and amateur riders," he said. "We're very fortunate to have some awesome people working and volunteering for us and a spectator can see virtually 95 percent of the track from any seat in the house which helps create an event-like atmosphere, and we've always been customer focused first and foremost."

Wylder said he expects a big crowd on Thursday and hopes it's big for the regular riders, sponsors and community that has kept them in existence for so many decades. All he and Ron really want for the 50th Anniversary race is anyone with a passion and appreciation of Motocross to watch and take in a Portland Main Event.

As far as the future of Thursday Night Motocross in Portland?

"It depends on who the President is," he said.