Meet the Team
Daniel Cooper
partner
Daniel is the founding partner of Sycamore Law, Inc. He was admitted to the California Bar in 1991, and has represented citizen plaintiffs in environmental advocacy for his entire career. Working with Law School clinics, Keepers, and environmental justice organizations, Daniel pioneered enforcement of the NPDES permit for industrial stormwater. Beginning with enforcement against closing military bases in the San Francisco Bay area, and expanding to cases attacking industrial stormwater pollution statewide, industrial stormwater enforcement has eliminated millions of pound toxic pollutants from urban waterways. Similarly Daniel initiated and sustained enforcement against dozens of municipal sewage systems, spilling tens of millions of gallons of raw sewage into neighborhoods, creeks, rivers and bays. New initiatives include State Law enforcement to obtain water for endangered fish, and Clean Water Act enforcement to transform urban water management in California and nationwide, integrating stormwater, wastewater, and drinking water into a single management system that mimics nature, protects receiving waters, and provides water supply resiliency in the face of climate change.
Daniel provides counsel to environmental advocates on advocacy, administrative processes, and litigation in state and federal court.
Jesse C. Swanhuyser
Partner
Jesse joined Sycamore Law in 2019 and works from the firm’s Santa Barbara office. Since graduating from UCLA Law School in 2011 with a specialization in Public Interest Law and Policy, Jesse has focused on advancing client’s interests through administrative advocacy and federal litigation under the Clean Water Act, the Federal Endangered Species Act, and the Resource Conservation and Recovery Act.
He began his public interest career in 1999 as a grassroots organizer advocating for the creation of a network of marine protected areas around California’s Northern Channel Islands. Following his service as a volunteer relief worker in Central America, Jesse co-founded and served as the first executive director at the California Fair Trade Coalition, where he spent nearly two decades as a campaign manager and lobbyist on behalf of environmental/environmental justice, indigenous and immigrants rights, small farming, and labor organizations fighting for responsible and fair international trade policy. In 2017, Jesse spearheaded the legal campaign to defend the Obama Administration’s rejection of the Keystone XL pipeline from an attack by TransCanada Corp. using the North American Free Trade Agreement (NAFTA).
At Sycamore Law Jesse supports the firm’s “Water for Fish” advocacy, and leads an innovating campaign aimed at integrating civil society’s enforcement of the Clean Air Act and Clean Water Act in California’s environmental justice communities, where air and water pollution threaten public health and the environment.
Hannah Mathieson
ASSOCIATE
Hannah joined Sycamore in 2024 and works from the San Francisco office. She graduated from UC Davis School of Law with certificates in Environmental Law and Public Interest Law. At law school, Hannah served as co-chair of the Environmental Law Society, participated in the Civil Rights Clinic, was inducted into the Order of the Barristers, and received the King Hall Moot Court Honors Board Member of the Year after receiving awards in oral advocacy and brief writing at the National Environmental Law Moot Court Competition and the National Native American Law Students Association Moot Court Competition. She also served as co-chair of the First Generation Advocates student group and as an Executive Editor for Environs, King Hall’s Environmental Law Journal.
Prior to law school, Hannah lived and worked in Japan before returning to the United States to work at Princeton University in New Jersey. In her free time, she enjoys reading, watching movies, hiking, and baking.
Hannah holds a B.A. in history and political science from Lewis & Clark College and a J.D. from UC Davis School of Law.
Kristina Hambley
ASSOCIATE
Kristina joined Sycamore in 2023 and works from the San Francisco office. She graduated from UC Davis School of Law, where she served as co-chair for the 2022 California Water Law Symposium and organized the 2022 Environmental Law Society Symposium. During law school, Kristina also served as a senior articles editor for Environs, King Hall's Environmental Law Journal, and participated in the Aoki Water Justice Clinic.
Prior to law school, Kristina contributed to the development and implementation of environmental grantmaking programs at the Leonardo DiCaprio Foundation, focusing on global conservation efforts and litigation to clean and protect water in the U.S.. As an attorney, she continues to be a fierce advocate for fishable, swimmable, and drinkable water in California. When she's not litigating, she enjoys hiking, long walks on the beach, and baking sourdough bread.
Kristina holds a B.A. in ecology from UCLA and a J.D. from UC Davis School of Law.