It turns east and then northeast past Lakeport, then flows northwest through the fertile Scotts Valley up to the outlet from the Blue Lakes.

The combined stream flows south through Rodman Slough into Clear Lake.

[7] It drains along Scotts Creek into Rodman Slough, which flows into Clear Lake.

Parts of Bachelor Valley may be flooded when Tule Lake backs up and passed through the culverts under highway 20.

[2] The watershed covers the Franciscan Complex, a wide variety of sedimentary rocks scraped up and attached to the advancing North American Plate.

The lake rose again, and created its present outlet via Cache Creek to the Sacramento River.

California State Route 20 runs across the northern part of the watershed from east to west.

[14] Grazing quickly led to the native perennial bunchgrasses being replaced by an annual grassland with grasses of European origin.

[16] Visitors from the San Francisco Bay Area and the Central Valley came for health or to vacation at the mineral springs resorts in Lake County.

[16] Commercial agriculture expanded in the early 1900s as better roads and railways made transport of produce more practical.

[16] In 1944 important crops in Scotts Valley included pears, walnuts, hop's and green beans, which were mainly grown in land reclaimed from the former Tule Lake.

[9] The headwaters of Scotts Creek on South Cow Mountain were severely burned in 2018 by the Mendocino Complex Fire, which may have increased erosion and the flow of sediments and dissolved nutrients into the Clear Lake.