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Exploring Old Mission Dam: A Historical and Ecological Treasure



Nestled in one of the largest urban parks in the United States, Old Mission Dam is a National Historic Landmark with a rich history dating back to the early 1800s. It was built by Spanish missionaries and the Kumeyaay people as part of a sophisticated water system for the Mission San Diego de Alcalá, California’s first mission. The dam captured seasonal rainwater from the San Diego River, providing a reliable water source for agriculture and daily life.


Today, the dam serves as a reminder of San Diego’s past and an entry point into one of the most ecologically diverse areas in Southern California. Learn more about the park’s history and conservation efforts on the Mission Trails Regional Park website.


What Makes This Hike Special?


Old Mission Dam is surrounded by diverse ecosystems, including chaparral, oak woodlands, and riparian zones. These habitats support a wide range of plants, birds, reptiles, and insects, making it a hotspot for exploration and learning.


The San Diego River ConnectionThe dam collects water from the San Diego River, which begins in the mountains of Julian and flows 52 miles to the Pacific Ocean. Along its journey, the river nourishes wetlands, provides drinking water, and supports numerous species. This natural resource is vital to the region’s biodiversity.


Biodiversity Highlights: What You’ll See


1. Native Plants and Their Importance 🌿

  • Coast Live Oak (Quercus agrifolia): This iconic tree provides food and shelter for countless animals.

  • California Sagebrush (Artemisia californica): Known for its pleasant aroma, it’s a favorite among pollinators.

  • Mule Fat (Baccharis salicifolia): Found near the water, this plant helps stabilize soil and prevent erosion.


Use the Seek app to identify these plants and learn how they contribute to the ecosystem!


2. Birds: A Birdwatcher’s Paradise 🐦Mission Trails is home to over 200 bird species, including:

  • California Quail (Callipepla californica): Often seen darting across trails in small groups.

  • Great Blue Heron (Ardea herodias): Graceful and striking, these waders are common near the dam.

  • Red-Tailed Hawk (Buteo jamaicensis): Watch for these majestic raptors soaring overhead.


Fall migration may bring additional visitors, such as warblers or white-crowned sparrows. Visit the San Diego Audubon Society for birding tips and more information.


3. Reptiles and Insects 🐛

  • Western Fence Lizard (Sceloporus occidentalis): Known as the “blue belly,” this lizard helps control Lyme disease by eating ticks.

  • Dragonflies: Often spotted near water, these insects are indicators of a healthy ecosystem.

  • Butterflies: Look for monarchs and swallowtails fluttering through the area.


Interactive Learning with the Seek App by iNaturalist


During our hike, we’ll use the Seek app to identify plants, animals, and fungi. This family-friendly app is easy to use and provides fascinating facts about your discoveries.


How to Use the App:

  1. Download Seek from Google Play or the App Store.

  2. Point your smartphone camera at a plant or animal.

  3. The app will identify the species and offer insights about it.


Pro Tip: Start using the app at home to familiarize yourself before the hike!

Why November is Special at Old Mission Dam


Late fall in San Diego offers cooler weather and unique opportunities for nature

observation:

  • Migratory Birds: Species like the White-Crowned Sparrow stop here during their journey.

  • Seasonal Vegetation: Many plants transition into dormancy, showcasing their rugged beauty.

  • Crystal-Clear Skies: Cooler air often brings excellent visibility, making it a great time for photos.


Why This Hike Matters for Families



At Eco Rangers, we’re committed to making learning fun and interactive. This hike is designed to:

  • Foster Curiosity: Kids will discover the world around them through hands-on exploration.

  • Teach Conservation: Learn how ecosystems work and why protecting them is important.

  • Build Connections: Meet other families and share the joy of outdoor adventures.


Whether it’s identifying a tree with the Seek app, spotting a hawk in flight, or simply enjoying the peaceful sounds of the river, this hike offers something for everyone.


Ready to Explore?

Let’s make this Thanksgiving unforgettable with a morning filled with discovery, laughter, and gratitude for the natural world. We can’t wait to see you on the trail!


Warmly,


The Eco Rangers Team



P.S. Don’t forget to download the Seek app by iNaturalist—it’s free, fun, and educational for all ages!



Learn More and Plan Your Visit


For more details about Mission Trails Regional Park, its history, and ongoing conservation efforts, visit the official website: https://mtrp.org/.


References:

  1. Mission Trails Regional Park Official Website: https://mtrp.org/

  2. San Diego Audubon Society: https://www.sandiegoaudubon.org/

  3. Seek App by iNaturalist: https://www.inaturalist.org/pages/seek_app


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