Though it is often discounted as one of the lowest performing local schools, Castro Elementary School is a "hidden gem" in the Mountain View Whisman School District, said Castro's principal.

"For so long it has been considered a school that may not be as worthy as other schools," Principal Judy Crates said.

But, Crates points out, Castro is home to the in-demand dual immersion program, which teaches children both Spanish and English from an early age. The school has raised its Academic Performance Index score by 350 points over the past 11 years -- moving from a very low 459 to a highly respectable 809 at the conclusion of the 2010-11 school year. The highest possible API score is 1,000.

The school has certainly come a long way since a 2003 audit found that the Castro was "not holding 'high academic expectations for all students.'"

"For Castro, the gain has been incredible," Crates said. "It's been a consistent upward trajectory."

Yet even as Castro has made great progress in the past decade, there is a perception among many living outside of the school's attendance boundaries that Castro is the same school it was back in 2003.

"I'm always on the defensive for Castro," said Jenna Adams a Castro parent, who is active in the Mountain View community.

Adams said that she is constantly encountering parents who consider Castro one of the worst, if not the worst, schools in the Mountain View Whisman School District. "There is so much emphasis on you want to go to Bubb or Huff," she said. "I think that decade-old perception still floats around."

Gaby Young, a parent of several Bubb children, lives on the border between the Castro-Bubb boundary. Young said she has long thought of Castro as a low-performing school. "I'm very surprised," she said, upon hearing that Castro had raised its API into the 800 range. "It's good news."

Much of the credit for the school's turnaround should go to Crates, according to Adams.

When she started her eldest daughter in kindergarten at Castro, Adams said things at the school were very "chaotic." After-school pickup of children was disorganized -- a problem Crates helped fix by working with the city of Mountain View. There was also no uniform writing program among all the classrooms when Adams' daughter started at the school, six years ago. Teachers "did their own thing," she said.

All that has changed, and many more improvements have been made to the school, Adams said. Not the least of which is school culture, which values and practices parent participation. "Everybody wants to learn about each other and get along," she said, "and everybody wants everybody else to succeed."

According to Adams, Crates also deserves much of the credit for fostering this attitude.

Crates, who joined the school in the 2008-09 school year, is willing to take some of the credit for the growth. Under her leadership the school's API broke 800, moving from a B to an A, according to California standards.

However, she said she couldn't have done it without her teaching staff and a community that is dedicated to Castro.

"The teaching staff is super dedicated," said Marcela de Carvalho, a third-grade teacher at Castro. Teachers at Castro tend to know every student at the school, she said.

Parents and the community are also played a large role in Castro's improvement, according to de Carvalho, who has been teaching at the school for six years. In that time, there has been a big push for parent involvement at Castro.

The push began when the district's PACT program took up a temporary three-year residence on the Castro campus. Although the PACT program -- which stands for "Parent, Child, Teacher" -- ultimately moved to Stevenson, it left a lasting, positive mark on Castro, according to de Carvalho. The residual impact of PACT, along with Castro's popular Spanish-English Dual Immersion program has meant that parents are highly involved with the school.

"Whenever you have more parent involvement, kids tend to do better in school," de Carvalho said.

"I tell people proudly that my kids go to Castro," said Nazanin Dashtara, who has put one of her daughters all the way through the school and has another daughter who still attends. Any parents who have misgivings about sending their children to Castro should put those thoughts aside, she said, pointing to the recent 809 API score as proof.

But even beyond the strides Castro has made to improve its API, Dashtara said, the school is strong in other ways. Dashtara, who does not live within Castro's attendance area, decided to send her eldest daughter to the school because of the dual-immersion program. On top of the great education she said her children have received in the Spanish-English program, the community at Castro is one of great warmth and understanding. "It's more than just being bilingual at this point," she said. "It's about being part of another culture and being part of a greater community."

Just as Crates gave credit to her teachers, de Carvalho also gave credit to Crates. "She is an awesome principal," de Carvalho said. "She makes the job of the teacher easier. She runs a tight ship."

Seeing her school's API score's rise so significantly in the time she has been there is "validating" for de Carvalho. She imagines that many Castro families feel the same, even if they may not show it. After all, she said, the school is "the best kept secret" in the Mountain View Whisman School District.

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