THE SEASON didn't begin all that well for the Salt Lake Trappers, who play in the Pioneer League, in baseball's lower reaches. "We started out 3-3," said their manager, Jim Gilligan. "I didn't see a lot of courage in the eyes of my pitchers."

But then the Trappers, an independent team made up of former college players who were passed over in the big-league draft, began to win. They started with back-to-back victories over the visiting Pocatello team, then took two from Idaho Falls. Three more wins followed in order, but it wasn't until the Trappers headed into Medicine Hat, Alberta, for a four-game stand that Manager Gilligan began to sense something was up. "I think the Medicine Hat series was a good one for us," he said, "because they had what I consider to be one of the great ball clubs we've played." The Trappers, by now hitting at a pace sufficient to put courage in the eye of every one of their pitchers, swept all four games, making it clear from Pocatello to Butte to Billings that if there was greatness in the Pioneer League this year, it resided in a place other than Medicine Hat.

The bus-borne Trappers continued to cut a swath through the league, winning night after night, week after week, until by late July their victory streak was approaching the all-time record for professional baseball. Last Saturday in Salt Lake City, fans began lining up six hours before game time at the stadium, and that night, before a full house of 10,000 plus many more who crowded onto rooftops near the park, the Trappers won their 28th consecutive game, breaking a record set by the Corsicana Oilers of the Texas League in 1902 and matched by the Baltimore Orioles of the International League in 1921.

After one more win, the streak ended Monday night in Billings, Mont., where the Trappers lost, 7-5. "They were really pumped up for the game," said a Trappers player of the Billings Mustangs. "We're in Cooperstown for winning 29, and they can say that they're the team that stopped it. They can take a lot of pride in that."

For all those big-league players who find that their guaranteed contracts make it hard for them to get motivated, a bit of advice: Take a trip to Pocatello some day when the Trappers are in town.