On Monday, Grade 6 students had their first visit of the school year to Mountain Lake in San Francisco.

The Hamlin School is situated within the urban confines of San Francisco. However, every year students have the opportunity to spend intensive days studying nature, collecting data, and participating in ongoing research work.

This hands on encounter with ecology takes place at Mountain Lake, a natural 1,700-year-old freshwater pond. “The area around Mountain Lake is home to 250 species of birds, 30 species of butterflies, 50 species of mammals, and more federally protected species than any other national park in the continental United States.” Spanish explorers who went on to settle San Francisco spent their first night camped by the lake in 1776.

In more recent years it was discovered that the entire lake was polluted. This was caused by dirty water run off from a nearby road, pesticides from the adjacent golf course, and people dumping non-native fish and turtles into the lake. The situation became so dire that the Presidio Trust had to kill all the fish in the lake with 50 gallons of rotenone, an odorless, colorless, poison. Once the water quality was restored, the Presidio Trust reintroduced non-invasive species better suited for the Mountain Lake environment.

Through the diligent work of faculty member Rachel Davis, Hamlin has been partnered with the Presidio Trust for a number of years. “The Presidio Trust is an innovative federal agency created to save the Presidio, (once a premier U.S. Army post) and share it with the public as a vibrant national park site.”

Over the years Hamlin students have:

-Collected data on birds for migration patterns

-Collected data on plants in order to look at climate change

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