First as a high school athlete at
San Gabriel High School she excelled in both Cross Country and Track, she then went to
East Los Angeles College where she not only won the 800, 1500 and 5000, but set
Community College records that have lasted over 20 years. and won the
California Community College Cross Country Championships in record time. She first found national attention by accident, using the 1986
Los Angeles Marathon as a training run. The televised race focused on this unknown runner leading the way, far ahead of favorite
Nancy Ditz, then suddenly dropping out almost 20 miles into the race. She had previously won the
Run Across Los Angeles 10 mile race in similar fashion, just because it fell between her college seasons. Due to the notoriety from the previous year, Mosqueda again ran the 1987 L.A. Marathon, this time finishing the race in 2:37:46, good for 2nd place overall. That same year she also won the
Philadelphia Distance Run Half-Marathon in 1:10:47. She was named
California College Athletic Association "Female Athlete of the Year" for 1987-1988. Next, Mosqueda went to
Cal State Los Angeles, where she won the 1987
NCAA Cross Country Championship and at the 1988
NCAA Women's Outdoor Track and Field Championships won the 10,000 metres title, setting the
NCAA national record of 32:28.57 in the process, a mark that stood for 30 years. As of 2015, she still holds the CSULA school records in all races from
800 meters to 10,000 meters. She was named the 1987 "Billie Jean King Woman of the Year. ==Olympic trials==