On top of the Rocky Mountain world five years ago with a Super Bowl team in his first year as a head coach, Red Miller hit rock bottom yesterday: first coach fired by a U.S. Football League team, first to be dismissed by both Denver football franchises.

Miller, resurrected by USFL's Gold two years since his 40-22 record didn't hold with NFL Broncos' new owner, now hears from Gold owner Ron Blanding after a four-game skid to 4-7:

"I don't want to lose any more games. We think the Denver Gold will go in a different direction without Red Miller at the stern."

Blanding and Miller irritated each other since training camp, coach openly criticizing owner for reluctance to spend on quality players; owner countering, "I don't appreciate reading in the papers every day that we have a lousy football team."

Offensive Line Coach Whitey Dovell leaves with Miller; Defensive Line Coach Charlie Armey is Miller's interim replacement, and began by acceding to players' request for a day off from practice: "I respect their wishes. Red was awful close to the players" . . .

San Diego's Chargers rebound from loss of first-rounder Gary Anderson to USFL by signing premier pick Billy Ray Smith, first defensive player taken in the NFL draft; long term, terms undisclosed . . .

Oakland Invaders had traded USFL rights to Smith to the Houston franchise that formally opened yesterday for 1984 business and, win some, lose some. The Houston owners had several NFL stars at their inaugural media conference--and Gene Burrough (Oiler Ken's brother), named general manager under Jerry Argovitz, player agent becoming general managing partner, saying, "This is Curtis Dickey, who is playing out his contract at Baltimore, and Billy Sims, who is playing out his contract with Detroit, and Joe Cribbs, who . . ."

And, holy Pete, they are (subject to league okay) the Houston Gamblers! Singer Kenny Rogers has a piece of the club, but partner Alvin Lubetkin said the nickname refers not to betting but to businessmen of the city's past:

"Those men . . . certainly took chances and that's what we want to project. When it's fourth and one, we are going for it. We may not even have a kicker" . . .

Turnover: Director Dick Garrison says 16 of the 38 Redskinettes for 1983 are new.