Welcome to the Arroyo Seco

The Arroyo Seco, Spanish for “dry gulch”, refers to both the stream course and the canyon that spans eight miles through the western portion of the City of Pasadena. Surrounded by urban development, the Arroyo Seco supports thriving natural ecosystems that include several native plant communities and provides shelter, food and nesting sites for hundreds of wildlife species. Efforts are underway by the city and local community organizations to protect, enhance and restore these ecosystems. Affectionately known to locals as simply “the Arroyo”, the Arroyo Seco in Pasadena is protected parkland and open space with 22 miles of trails and myriad recreational opportunities. The Arroyo Seco was recently included in the National Register of Historic Places, placing it among the nation’s top cultural resources.

Arroyo Seco Plans and Projects

The Arroyo Seco landscape provides the habitat to sustain the rich biodiversity found within this breathtaking canyon. However, over the last few centuries, human impacts on the Arroyo have taken their toll, compromising the integrity of this vital landscape. Efforts to restore the habitat and mitigate the human impacts have been underway for the past few decades. Following is a brief list of a few recent restoration projects:

  • Stream Diversion in the Lower Arroyo
  • Central Arroyo Stream Restoration
    • Concrete Removal beneath I-210
    • Reintroduction of Arroyo chub to Central Arroyo
    • Parking Lot Improvements
    • John Crowley Trail Restoration
  • Archery Range Planing Restoration
  • Memorial Grove Planing Restoration

Caring for the Arroyo Seco and managing the resources is a process involving the participation of the City of Pasadena, county agencies, regional and local conservation and community organizations, and members of the community. Collaboration and participation between these individuals and groups is essential. Participating in the process benefits us all!

Arroyo Seco
Canyon Project

The Arroyo Seco Canyon Project, a partnership between the City of Pasadena Water and Power Department and the Arroyo Seco Foundation, is a water resources enhancement, habitat restoration, and recreation improvement project funded by the state integrated regional water management program and Pasadena Water and Power. Project benefits include:

  • Increasing local water supply
  • Enhancing water quality
  • Restoring aquatic and riparian habitat
  • Improving passive recreational opportunities

Planning Process and Documents

Arroyo Seco Master Plans

The Arroyo Seco Master Plans are a set of documents defining the community vision for the Arroyo Seco Natural Park. The set is comprised of four separate planning documents.

Arroyo Seco Design Guidelines
Central Arroyo Master Plan
Hahamongna Watershed Park Master Plan Addendum - Initial Study
Lower Arroyo Master Plan

Environmental Review Process

Planning, construction, and restoration projects in the Arroyo Seco are subject to an environmental review. To learn more about this process, visit the Planning & Community Development webpage on the environmental review process.

Culture, History, and Society of the Arroyo Seco

Affectionately known to locals as simply “the Arroyo”, the Arroyo Seco has been treasured by residents of the San Gabriel foothills for centuries. Known as the birthplace of Pasadena, the Arroyo has factored prominently into the culture of the first people to seek refuge at the base of the San Gabriel Mountains to the present day urban communities. Today, we admire the Arroyo’s beauty, celebrate its ecological diversity, and protect its heritage. Recently included in the National Register of Historic Places, the Arroyo has been identified as one of America’s top cultural resources. For more information, visit City of Pasadena’s City Heritage webpage.

The Vision for the Parkland

As early as 1887, the citizens of Pasadena recognized the land surrounding the Arroyo Seco should become a park for the enjoyment and benefit of the public. It is claimed President Theodore Roosevelt visited the Arroyo Seco in 1911 and is quoted as saying, “This Arroyo would make one of the greatest parks in the world.” Between 1911 and 1927, the City of Pasadena accumulated the land for what is now the Central and Lower Arroyo. In 1919, the area now known as Hahamongna Watershed Park was annexed to the city by popular vote. The land was then leased to the County of Los Angeles for the construction of Devil’s Gate Dam as well as for the mainteneance of a reservoir for water conservation and flood control purposes.

In 1918 the Arroyo Park Committee, headed by architect Myron Hunt, suggested that a comprehensive plan be developed by noted landscape architect Emile Mische. The plan recommended that the Lower Arroyo be reserved for trails and bridle paths and planted only with native plants. In 1977, the City declared the Lower Arroyo to be a City Cultural Landmark. In the last two decades of the twentieth century, the City of Pasadena began the process of resuming management of the area north of Devil’s Gate Dam and converting it from a land of harvest and production to protected parkland. The land was named Hahamongna Watershed Park.

In the late 1990’s the City of Pasadena, in partnership with community members, engaged in a visioning process to develop the  Arroyo Seco Master Plans . The plans define a community vision for the preservation, management, and restoration of the Arroyo Seco Natural Park–a park incorporating all three park areas into one. The Arroyo Seco Master Plans were adopted by City Council between the years 2003-2005. After years of park planning and development, the Arroyo Seco Natural Park totals nearly 1,000 acres today, distinguishing it as Pasadena’s largest and most diverse park. No doubt, President Roosevelt would be very pleased to see the great park this land became.

A Legacy of Stewardship

The land now famous for the Tournament of Roses, the Rose Bowl, the Jet Propulsion Laboratory, and California Institute of Technology, was once occupied by the Tongva. Subsisting on local game and vegetation, the Tongva lived in villages scattered along the Arroyo Seco and the canyons from the mountains down to the South Pasadena area.

The Tonga have a long history as stewards of this land. Each year, following the seasons, they collect botanical material for traditional spiritual, ceremonial, medicinal and utilitarian uses. As guardians of these natural resources, they understand how to collect in a way that does not impair the sustainability of the plant population. As custodians of their culture, individuals, families and tribal groups use sites throughout Hahamongna Watershed Park for spiritual, social, and ceremonial traditions.

Arroyo Landmarks and Points of Interest

Colorado Street Bridge

Built in 1913, the Colorado Street Bridge gracefully rises 150 feet above the Arroyo Seco stream connecting Pasadena with the Eagle Rock community to the west. Known for its distinctive Beaux Arts arches, the bridge significantly reduced the time required to cross Arroyo Seco canyon. In 1981 the bridge was added to the National Register of Historic Places.

Devil’s Gate Dam

Originally built in 1920, and later reinforced in 1998, this is the first dam built for Los Angeles County’s flood control and water conservation system. Its name is derived from a unique rock formation below the dam that resembles the profile of a horned devil. In 1858, when Judge B.S. Eaton visited the site of the Arroyo Seco, he named the location “the Devil’s Gate.” The formation has since been covered during restoration of the dam and is no longer visible.

Flint Wash Bridge

This bridge, built of sustainable materials and opened in 2007, offers year-round access for pedestrians, equestrians and bicyclists to a full trail loop around the Hahamongna basin.

Spreading Basins

Large basins in the bed of the stream can be found on the eastern side of Hahamongna Watershed Park flood basin. These spreading basins are used by the City of Pasadena to recharge the aquifer with water from the Arroyo Seco stream. The aquifer contributes to much of the municipal water supply.

Stream Restoration

South of the Colorado Street Bridge are several low-flow streams. These streams were constructed in 1997 as part of a restoration effort in the Lower Arroyo, and mimic what the area resembled prior to construction of the flood control channel. Willows and other riparian vegetation flourishing along the streams provide habitat for several native species.

Memorial Grove

In the center of the Lower Arroyo is the Memorial Grove. Planted with a variety of native tree species, the Memorial Grove commemorates community members who have passed on.

Camel’s Hump

Toward the southern end of the Lower Arroyo, the Camel’s Hump rises from the Arroyo Floor. Once a spur ridge deflecting the Arroyo Seco’s natural flow pattern, the “hump” was split in two during the construction of the Arroyo Seco storm channel.

The Natural Environment

The Arroyo Seco contains a dynamic stream that begins high in the San Gabriel Mountains and flows through the communities of La Canada Flintridge, Altadena, Pasadena, South Pasadena and Los Angeles, where it meets the waters of the Los Angeles River and continues on to the Pacific Ocean. In making this journey, the stream cuts a narrow, deep canyon through these communities and gave birth to much of the culture, history and unique identity within the region of this riparian corridor.

The Arroyo Seco Watershed

The Arroyo Seco Watershed encompasses a total area of approximately 47 square miles. The towering San Gabriel Mountains define the upper watershed boundary shedding water into the Arroyo Seco, a 22 mile long stream. The Arroyo Seco passes through a landscape of rugged mountain terrain, narrow canyon land, and fertile floodplain before it joins with the waters of the Los Angeles River eventually draining into the Pacific Ocean.

Ecology of The Arroyo Seco

Steep slopes, the presence of water, periodic flooding, and natural geography of the canyon contribute to the rich diversity of plant and animal life found in the Arroyo Seco.

Learn More About the Natural Environment in The Arroyo

Recreation, restoration, and conservation events are hosted year round in the Arroyo by organizations and groups. For more information on groups regularly hosting events in the Arroyo , please visit their websites:

Sights and Sounds of the Arroyo Seco

The beauty and unique character of the Arroyo Seco has captured the hearts of recreationists, preservationists, and nature lovers for generations. Visits to this enchanting canyonland have inspired artists, filmmakers, and writers to create works telling the story of this complex beauty of this dynamic landscape. Continue reading below to find two films inspired by the Arroyo Seco.

Film: Pasadena’s Arroyo Seco, a Park for All People

Created for the City, Pasadena’s Arroyo Seco, A Park for all People, highlights the natural, historic, and cultural worth of the Arroyo Seco.

Film: A River’s Journey to Rebirth

The Central Arroyo Seco Stream has been restored as a pilot project to reestablish habitat for native species. The film, A River’s Journey to Rebirth, illustrates the story of this restoration project.

Part 1

Part 2

Part 1

Part 2


The Arroyo Seco Natural Park is the City’s largest natural open space with 22 miles of trails and myriad recreational opportunities. It is a passageway for both wildlife and people, linking its trails to those of the Angeles National Forest and the Rim of the Valley trail system. This network of trails provides opportunities for short leisurely strolls or day long adventures, just minutes from bustling metropolitan areas.

In addition to the miles of trails, the Arroyo Seco Natural Park offers a variety of recreational facilities: playgrounds, multipurpose fields, specialty sport fields, an aquatics center, a museum, a golf course, a world class sports stadium, and more!

Recreational Facilities

In the 900 acres of the Arroyo Seco Natural Park one can golf, swim, run, walk, jog, bike, picnic, bird-watch, play ball, fly a kite, play disc golf, flycast, shoot a bow, watch a world class football game at the Rose Bowl, and more. Click on the links below to learn more about the facilities.

Aquatics Center
Archery Range
Bird Sanctuary
Brookside Golf Course
Brookside Park
Casting Pond
Disc Golf Course
Equestrian Facilities
Hahamongna Watershed Park
Kidspace Children’s Museum
La Casita del Arroyo
Multipurpose Fields
Picnic Areas
Rose Bowl Stadium

Facility Reservations

Information on facility reservations is available through the Parks, Recreation and Community Services Department.

Reserve now

Trail Use Guidelines

Trails in the Arroyo Seco are open from sunrise to sunset, 365 days a year. All trails in the Arroyo Seco are open to walkers, hikers, or joggers. Equestrians are welcome on most Arroyo Seco trails, although not recommended on the Rose Bowl Loop or Brookside Fitness Trail. Cyclists are welcome on paved roads throughout the Arroyo Seco as indicated on park signage. On leash dogs can enjoy the trails, too, so bring along Fido—(just be sure to clean up after your pet.) Stay on the trails and remember to share the trail with other users.

Other Recreational Opportunities

Recreation, restoration, and conservation events are hosted year round in the Arroyo by organizations and groups. For more information on groups regularly hosting events in the Arroyo , please click on the links below.

Archery Range

Lower Arroyo Archery Range

The Lower Arroyo Seco contains a northern and southern archery range and is used for organized events, competitions and informal practice.  Additional information about these ranges is provided below.  This area is open to the public when not in use for an organized event or activity.  The Pasadena Roving Archers has been a part of that history and is charged with the responsibility of maintaining the range and managing organized archery activities.

Northern Range

  • This range is permitted for archery use only for permitted events (not more than 13 per calendar year) according to the following northern range use schedule 2017-2018 Northern Range Schedule
  • During these events temporary targets and signage about the activity are used

Southern Range

  • This range contains 28 hay bale targets and 6 practice butts
  • This range is used for archery during park hours for the Lower Arroyo (sunrise to sunset)
  • The range is permitted to the Pasadena Roving Archers according to the times specified in the southern range use schedule 2017-2018 Southern Range Schedule
  • Outside of times the range is reserved by permit, it is open for archery use by individuals possessing a city-issued credential

What Are The Archery Range Use Requirements?

  • Pursuant to the Lower Archery Range Rules (listed below), persons wishing to use the Lower Arroyo Archery Range must obtain a city-issued archery credential
  • Archery credentials can be obtained upon successful completion of a City-approved class on range safety and basic archery instruction offered by the Pasadena Roving Archers
  • For more information about the class on range safety and basic archery instruction, please contact the Pasadena Roving Archers at (626) 460-0520.

Where Is The Range Located?

The Archery Range is Located in Lower Arroyo Seco. The main entrance to the Lower Arroyo is located off South Arroyo Blvd.

Directions to the Lower Arroyo Main Entrance.

Who Should I Contact For More Information About Organized Classes or Events?

The Pasadena Roving Archers are responsible for offering archery lessons and maintaining the range.
Archery lessons, hosted by the Pasadena Roving Archers, are offered to the public on Saturdays between 8:30 am and 2:30 pm. First-time participants are offered a free lesson. The range is also reserved for organized use by the Pasadena Roving Archers on Sundays between 8:30 am and 2:30 pm.

The club contact information is:

Pasadena Roving Archers
P.O. Box 683
Pasadena, CA 91102
(626) 460-0520

Lower Arroyo Archery Range Rules

  1. Individuals must prominently display City issued archery credentials when using the Lower Arroyo Archery Range.
    Exceptions include students under the direction supervision of instructors certified by USA Archery or NFAA and USA Archery or NFAA members participating in their first PRA-sponsored event (and are capable of producing membership materials)
  2. Non-archery activities are prohibited within the boundaries of the Lower Arroyo Archery Range
  3. Practicing archery outside of the boundaries of the Lower Arroyo Archery Range is prohibited.
  4. Broadhead arrows, crossbows, sling shots, knives, hatches and firearms (including BB, pellet, paintball guns or air riles) are prohibited.
  5. Sky drawing (aka sky loading) is prohibited. Arrows shall be pointed down or at the target only while being drawn.
  6. Arrows shall not be shot from a position beyond the farthest marker in any shooting lane.
  7. When retrieving arrows, all archers shall walk forward together.
  8. When searching for lost arrows, someone shall be posted in front of the target bale and/or lean a bow across the target bale to alert other archers of your presence.
  9. Care for the protection of land and wildlife shall be shown at all times.
  10. Should people or animals appear between an archer and the target, bows shall not be drawn.
  11. Alcohol and smoking are prohibited within the Lower Arroyo Archery Range.
  12. The Lower Arroyo Archery Range is open during park hours for the Lower Arroyo (sunrise to sunset). The range is open for public archery except when:
    Being used for organized activities by the Pasadena Roving Archers according to a City approved use schedule
    b. Reserved by another individuals or organization with a City permit or other City authorization.
  13. Children under age of 12 must be accompanied by an adult.
  14. Credential must be renewed every three years.
  15. Arrows may only be shot from designated shooting locations (distance markers)
  16. Arrows must be clearly marked with shoot identification information

In addition to the rules enumerated above, all other rules and laws applicable to the City’s parks are applicable within the Lower Arroyo Archery Range. (Pasadena Municipal Code 3.24 Article 3 Use Restrictions).  Violations of rules for the Lower Arroyo Archery Range will be subject to general penalty provisions set forth in Chapter 1.24 of the Pasadena Municipal Code.

Arroyo Safety

The Arroyo Seco is a dynamic landscape providing visitors the thrill of experiencing a living environment. As is typical of a natural setting, conditions in the Arroyo Seco can be undpredictable. It is important to be familiar with the potential dangers. Avoid approaching, feeding, or touching animals. Be aware of mountain lions and rattlesnakes. Avoid contact with poison oak.

Plan Your Visit

  • Tell someone where you plan to be in the Arroyo.
  • Carry enough water to keep you hydrated during the time of your visit.
  • Wear sturdy shoes, sunscreen, a hat, and helmet (if you are riding horses or bikes.)
  • From fall through spring, be sure to wear layers as weather conditions can change unexpectedly.
  • Be respectful of all plants, animals, and people you encounter within the Arroyo

Trail Use Guidelines

Trails in the Arroyo Seco are open from sunrise to sunset, 365 days a year. All trails in the Arroyo Seco are open to walkers, hikers, or joggers. Equestrians are welcome on most Arroyo Seco trails, although not recommended on the Rose Bowl Loop or Brookside Fitness Trail. Cyclists are welcome on paved roads throughout the Arroyo Seco as indicated on park signage. On leash dogs can enjoy the trails, too, so bring along Fido—(just be sure to clean up after your pet.) Stay on the trails and remember to share the trail with other users.

Additional Information

Please remember: the Arroyo Seco is a dynamic system that can change from a trickle to a roaring river in short order and without warning. In the event of rain, please keep away from the streambed and move to high ground.

Mountain Lions in the Arroyo
Poison Oak in the Arroyo
Rattlesnakes in the Arroyo