Nicasio Reservoir, located in Marin County, California, is a 845-acre artificial lake created by the construction of Seeger Dam in 1961. The reservoir sits within a 35.9 square mile drainage basin, surrounded by rolling hills and picturesque vineyards. While primarily used for fishing and hiking, paddling opportunities are limited due to restrictions on boating access.

The reservoir does not have boat launches, which significantly impacts paddling activities. Visitors can access the water's edge from multiple parking areas along Nicasio Valley Road, which offers free and accessible parking. The shoreline provides opportunities for bank fishing and hiking, with a 3-mile trail along the water's edge offering expansive views of the reservoir and surrounding landscape.

Wildlife enthusiasts may spot various species around the reservoir. A river otter was documented at the southwest corner in 2008, and the area is home to diverse bird life. Largemouth bass, crappie, and catfish populate the waters, with some bass reaching sizes over 10 pounds.

The reservoir's broad and shallow nature leads to quick evaporation, which may affect water levels throughout the year. Water quality is a concern, as the California Office of Environmental Health Hazard Assessment has issued a safe eating advisory for fish caught in Nicasio Reservoir due to levels of mercury or PCBs.

Paddlers should be aware that the reservoir can get quite hot during summer days, making early morning or evening the most comfortable times for shoreline activities. The area experiences significant traffic, which may impact the tranquility of the experience.

The construction of Seeger Dam was controversial, displacing local farms and blocking spawning areas for endangered coho salmon and threatened steelhead trout. This history has shaped the current ecosystem and usage of the reservoir.