High winter flows in Los Trancos Creek are diverted by Stanford's Lagunitas Diversion Dam just downstream from Rossotti's to Felt Lake.

[4] Its headwaters are protected by the Los Trancos Open Space Preserve just northwest of Page Mill Road.

In 1929 Stanford installed a diversion dam on Los Trancos Creek to its Felt Lake water storage reservoir.

The dam, located just below the intersection of Arastradero and Alpine Roads, blocked access of anadromous steelhead trout (Oncorhynchus mykiss) to over 3 miles (4.8 km) of pristine upstream spawning grounds.

[9] The upper watershed is wholly protected within the Los Trancos Open Space Preserve just northwest of Page Mill Road and east of Skyline Boulevard.

[10] From 2016 through 2020, a pair of bald eagles (Haliaeetus leucocephalus) has nested in a large eucalyptus tree near Felt Lake and the Pearson-Arastradero Preserve.