The Colorado Rockies' 1999 season was the seventh for the Major League Baseball (MLB) franchise located in Denver, Colorado, their seventh in the National League (NL), and fifth at Coors Field. The team competed in the National League West, finishing in fifth and last place with a record of 72–90. Jim Leyland, a longtime manager in MLB, debuted as the Rockies' new manager, and resigned following the season.
The Rockies, along with the San Diego Padres, made MLB history on Opening Day, April 4, 1999, by playing a contest in Estadio de Béisbol Monterrey in Monterrey, Mexico, making it the first Opening Day game held outside of the United States or Canada. Larry Walker won his second batting title by leading MLB with .379 average, setting a Rockies' club record, and the fourth-high single-season average since Ted Williams hit .406 in 1941. Besides winning the batting championship, Walker also led the major leagues in on-base percentage (.458), and slugging percentage (.710), becoming the first player to lead MLB in all three categories since George Brett in 1980, and the first National Leaguer since Stan Musial in 1943. Despite the team hitting quite well and appearing in the league's top 4 teams in hits, runs, and batting average, the team's performance was poor; the pitching staff performed awfully, allowing 1028 total runs - a mark that, as of 2023, has not since been surpassed by any team. The team set franchise records in earned runs surrendered, walks issued, hits allowed, and ERA. The pitching staff combined for an ERA of 6.01, a new franchise-worst record that has also not since been surpassed by any team.
Offseason
October 29, 1998: John Vander Wal was traded by the Colorado Rockies to the San Diego Padres for a player to be named later. The San Diego Padres sent Kevin Burford (minors) (October 29, 1998) to the Colorado Rockies to complete the trade. November 9, 1998: Brian Bohanon and Lenny Harris were signed as free agents by the Colorado Rockies. November 20, 1998: Jason Bates was released by the Colorado Rockies. December 18, 1998: Henry Blanco was signed as a free agent by the Colorado Rockies.
Regular season
On April 4, 1999, the Rockies made history as they played their Opening Day contest at Estadio de Béisbol Monterrey in Monterrey, Mexico, marking the first time Major League Baseball (MLB) commenced the regular season outside of the United States or Canada. Their opponent were the defending National League champion San Diego Padres. Vinny Castilla, a native of the southern Mexican state of Oaxaca, delighted the crowd with four hits including a double. Dante Bichette also collected four hits, drove in four runs, and homered, as Colorado won 8–2. The official attendance was 27,104.
The Rockies' scheduled home games against the Montreal Expos on April 20 and 21 were both postponed in the aftermath of the Columbine High School massacre in which 15 people, including both shooters died. The Rockies then added a "CHS" patch on the right sleeve of their jerseys which they wore for the remainder of the season.
On April 28, right fielder Larry Walker hit three home runs against the St. Louis Cardinals for his second career three home run game while contributing eight RBI in a 9–7 win.
In the May 19 contest versus the Cincinnati Reds, the Rockies were on the losing end of a 24−12 final, tied for the fourth-highest run-scoring output in MLB history. The Reds' Jeffrey Hammonds hit three home runs; following the season, Colorado acquired him via trade. Both Hammonds and Sean Casey totaled four hits. Casey went on base seven times with three walks, scoring five runs, and hit two home runs and six RBI. The Reds totaled six home runs; Brian Johnson hit the remainder. Both Walker and Bichette had four hits. Bichette also had five RBI, and Castilla hit a three-run home run. Walker raised his season average to .431.
From June 18−23, Walker tied Bichette's club record by homering in five consecutive games. The following day, Walker tied another club record, held by Andrés Galarraga, with his sixth consecutive multi-hit game. On July 8, Walker hit his 250th career home run versus Chan Ho Park of the Los Angeles Dodgers.
Carrying a .382 first-half average, Walker had batted .390 (189 hits in 484 at bats) from the 1998 All-Star break to the same point in 1999, the equivalent of a full season. He was named to his third consecutive All-Star team. In the July 19 contest versus the Oakland Athletics, Walker became the second player to homer into the plaza reserve seating of the Oakland Coliseum, following Mark McGwire, who had done so three seasons earlier.