AMA Motocross makes Colorado return.

Thunder Valley Motocross Park is set to host round seven of the 2005 AMA Motocross Championship presented by FMF this weekend, marking the first return of the series to Colorado since the 1980s.

Defending champion Ricky Carmichael headlines the host of motocross stars set to compete at Thunder Valley for the first time, and the runaway 2005 championship leader will aim to build on his already 71 point lead - the biggest mid-season lead in the history of AMA Motocross.

The undefeated since 2003 Carmichael is coming off a record setting 21st consecutive national victory last weekend in New Berlin, where he won despite a scary crash in which he and Kawasaki's James Stewart came together coming off a jump. Carmichael's last loss came in Washougal, on July 27, 2003 when Kevin Windham took victory.

"I've only been to Colorado once in my life," said Ricky. "I think it's great that we're going to that part of the country. I know the fans there are into motocross big time and hopefully we can put on a good performance for them. The track will be a challenge, especially considering the elevation. It's going to be important to find a good set up there pretty quickly, so that puts a little additional pressure on the teams."

While Carmichael is on cruise control heading for his sixth straight AMA 250 Championship, the battle for runner-up in the series is heating up between Yamaha's Chad Reed and Honda rider Windham.

Reed held second for the first half of the season, but Windham has come on strong in recent rounds. He won a moto at Unadilla for the first time in nearly two years and hopes to keep his drive going in Colorado.

"It was nice to get a moto win at Unadilla," Windham said. "I seem to be building a bit of momentum and I'd like to keep that going. Colorado is going to be new to everyone so we are all starting from scratch."

Another one of the marquee riders Colorado fans are eager to see in person is Stewart, but the rider who broke many of Carmichael's records in the 125 class is finding the going a little tougher in the 250 ranks.

Stewart crashed together with Carmichael last week and did not race in the second moto, but is expected to compete at Lakewood. Stewart is one of the few remaining riders competing on a 250cc two-stroke powered machine. Most of the other teams have switched to the 450cc four-stroke engines. Stewart tested a four-stroke Kawasaki at Lakewood, but is expected to remain on the two-stroke this weekend.

Veteran Mike Brown comes to Colorado leading the 125 class on his privateer Honda, but Brown's points lead has been shaved down in the last two rounds. He now leads Monster Energy Drink Kawasaki's Ivan Tedesco by 16 points at the halfway point in the season. Rookie Mike Alessi stands third in the rankings on the Red Bull KTM.

Four riders, Grant Langston, Brown, Alessi and Broc Hepler, all have scored victories in the 125 class this year. Hepler scored his first national win last week in New York.

Thunder Valley hosted AMA Motocross Championship races in the 1980s. The facility has been greatly improved since the series last visited.

Honda factory 125cc rider Andrew Short is a Colorado native and grew up racing at Lakewood. He says the area is more than ready to host an AMA Motocross Championship event.

"Colorado loves motocross and racing in general," Short said. "Denver is a big sports town, so it has all the ingredients to make a successful event. I think a lot of people from places like Oklahoma, Texas, New Mexico, Arizona and all those people that love motocross, but don't get to see their heroes' race - it's going to be easy for them to go now and that's why people are so excited about it."