El Rio Preserve
Your Resource for Preservation, Education & Recreation at El Rio Preserve
About the Preserve
El Rio Preserve is a 104-acre site that has served a variety of uses for many years. In the 18th century, Juan Bautista de Anza and his followers camped on this site during their journey from Southern Arizona to San Francisco. More recently, the Arizona Department of Transportation used this location as a gravel borrow pit for large infrastructure projects. Over the past several decades, disc golfers have constructed a series of targets throughout the site, and periodically, the flood waters from surrounding neighborhoods have created a seasonal lake, attracting a variety of migratory birds.
Note: The El Rio Preserve is beginning a remediation project to restore the health and beauty of its lake. Starting in early October 2025, the lake will be temporarily drained to allow for the removal of cattails and organic muck buildup that has reduced water quality over time. The project, scheduled for completion by the end of November, will result in cleaner water, fewer nuisance nutrients that trigger algae blooms, and a more balanced mix of aquatic plants. These improvements will not only benefit the lake’s ecosystem but also create a more enjoyable and scenic experience for everyone who visits El Rio.
Location
El Rio Preserve
10190 N. Coachline Blvd
Marana, AZ 85743(PDF, 2MB)
Directions
Assets of El Rio Preserve
El Rio Preserve offers the community several benefits including:
- Rich riparian habitat for nesting and migratory birds. More than 200 species of birds have been observed here.
- Stormwater retention basin that prevents flooding of nearby neighborhoods.
- El Rio is one of the links in the chain of preserved riparian habitat along the Lower Santa Cruz River, including sites such as Sweetwater Wetlands and Kino Environmental Restoration Project.
- Natural land features, like mounds and shade trees, that support a variety of land uses and nature viewing.
- Site is identified as a regionally important wildlife linkage.
- Any added features must be compatible with the characteristics of natural habitat and wildlife linkage.
Award-Winning
El Rio Preserve was the recipient of the 2022 Natural Resources Award from the Arizona Parks and Recreation Association.
Read More Here(PDF, 519KB)
El Rio in the News
Outdoor Recreation Programs
Birds, bugs, bats, and more are waiting for you to explore at El Rio Preserve. Join us for guided treks and hikes, observe the local fauna and flora throughout the seasons, or learn about the cultural history of the area - all in one scenic location.
Register for Recreation Programs at El Rio Preserve
Friends of El Rio
The Friends of El Rio Preserve works with partners to protect and enhance habitat at the Preserve, promote compatible recreational activities, and educate about the Preserve’s unique natural resources.
Learn More about Friends of El Rio
Birding in Marana
Birding (i.e. bird-watching) has become a wildly popular recreation in the United States. Southern AZ is known as one of the premier bird hot spots in the country and El Rio Preserve is a destination location to birdwatch in Marana.
Learn More about Birding in Marana
Preserve Information
Tucked into a pocket of the upper Tucson Mountains, El Rio Preserve functions as a collecting basin for both run-off from the mountain slopes and overflow from the Santa Cruz River. This confluence of geologic features affords spectacular views of granite and gneiss intermixed with the younger volcanic rocks that produce the vibrantly red hues that distinguish these peaks. To the east is a wide-open flood plain of the lower Santa Cruz River, which occasionally becomes a turbulent waterway after heavy rains.
Los Morteros Conservation Area
Located south of Marana’s El Rio Preserve, the Pima County Los Morteros cultural resources site is currently receiving enhancements to improve the educational opportunities and recreation experience as a cultural resources park. Part of Pima County’s cultural preservation program, the Los Morteros site and two other properties were previously acquired to protect the cultural resources. At the time of purchase, protective fences were installed around the site with a single access gate on the southern boundary at Linda Vista Boulevard.
Phase two of work at the Los Morteros Conservation Area provided at-grade decomposed granite paths following the existing dirt trail throughout the site, interpretive signs at key locations on slab mounted bases to minimize disturbance, and a new northern pedestrian gate at Coachline Road. The new northern pedestrian gate connects to sidewalk and a crosswalk built by the Town of Marana. This links the Los Morteros Loop to the El Rio Preserve trailhead and the Chuck Huckelberry Loop. This project is a collaboration between the Pima County Flood Control District and the Pima County Office of Sustainability and Conservation, and the improvements were constructed by Hunter Contracting Co with a cultural resources monitor from Desert Archeology present throughout construction.
Review the below “El Rio Recreation Area” map for perspective of the close proximity Los Morteros Conservation Area location. Patrons can park at our existing trailhead parking lot at the El Rio Preserve, walk across Coachline Road using the crosswalk, and enter the Los Morteros area to enjoy this pedestrian amenity.
View El Rio Recreation Area Map(PDF, 2MB)
Stay in-the-know with all Town of Marana projects and initiatives.
Marana Project Info Website
Helpful Links