Hiking Santiago Oaks Regional Park to Irvine Regional Park — The Short Loop


Santiago Oaks Regional Park to Irvine Regional Park: Santiago Creek-Egret-Willow Trail Loop

Date Hiked: October 22, 2011
Best Season: Autumn Spring Winter
Check Trail Conditions: Santiago Oaks Regional Park (714) 973-6620 or (714) 973-6622, and Irvine Regional Park (714) 973-6835 or (714) 973-3173
  • Distance: 5.2 miles round-trip
  • Elevation Gain: 147 feet
  • Route Type: Partial Loop
  • Trail Type: Dirt, with a couple of creek crossings
  • Difficulty: Moderate

Santiago Oaks Regional Park is one of our favorite local hiking spots, giving a near-wilderness feel right in the middle of town.  Very popular with mountain bikes and horseback riders, we’ve written up several of our favorite hikes there in the past (See Inner Loop and Robber’s Roost to Weir Canyon), and have also spent a lot of time at another of our favorites, nearby Irvine Regional Park, which we’ve also written about.  Combining the two parks is quite easy, and something we’ve now done a few times, with a couple different ways to hike between them.

This particular one is the shortest way to make the journey.  You could start either at Irvine Regional Park or at Santiago Oaks Regional Park, but we’ve always started at Santiago when we’ve done it (though having ice cream at Irvine Regional Park isn’t a terrible way to end a hike…).

As you enter the park, you’ll hit the fee kiosk, where you pay your parking fee (unless you have an annual pass) and usually can pick up a trail map.  Pull into the parking lot, and head east down the stairs towards the Santiago Oaks Trailhead (or you can take the Historic Dam Trail, which pretty much puts you at the same place).

Ample parking! Most of the time, anyways...

The Santiago Trail head is off to the left, across the creek, but there are doggy bags, a watering station, and a map near that kiosk there.

Crossing the creek near the parking lot. Sometimes the water level is much higher and faster. If it is a lot higher and faster than this, check with the rangers before attempting to cross the other two crossing on this hike.

Cross the creek on the concrete steps, and turn right down the main Santiago Trail.  The trail is mostly shaded and probably the prettiest year-round trail in the park.  You can check out the overlook at the Historic Dam, which is pretty cool and has a little plaque explaining the historical significance of it.

The shaded first stretch of the Santiago Trail, our favorite part of the park.

The historic submerged dam, from the overlook.

Info kiosk above the historic dam.

Oak Trail heads towards the left to get to Robber's Peak. Stay right on Santiago Trail.

Junction with Pony Trail. Take it to the right.

About a third of a mile along the trail, you’ll come to the Pony Trail.  When there is water in the creek, this is a popular trail for dog owners and people who want to play in the water.  In wet seasons, you may have to wade to cross this piece of creek.  In dry seasons, it may be completely barren.  Usually it is somewhere in between.  If you do take this route (which I recommend, especially if you want to duplicate as little of the path as possible), you will quickly come to a corral, which makes it look like you’ve left the trail and park entirely.  But if you go across the corral, you will re-find the trail on the other side, which you can then take on up the hill to the top of the big dam, passing a left turn back down to Santiago Trail along the way (which you’ll return on later, if possible).

One potential crossing at the Pony Trail.

On this day, there was an easier crossing just left of where the Pony Trail hit the creek.

Just past the creek, you'll come to this sign announcing the end of the park. Ignore it, and continue across the corral.

Approaching the corral.

The other side of the corral. Ignore the trail to the left (for now) and head straight up the road alongside the dam.

View from the top of the dam. Middle peak is Robber's Roost, which we've written about before. Peak on the right has a scenic overlook we've also written about elsewhere.

The trail to the top of the dam is paved.

Once across the top of the dam (just less than a mile in), the high point of the trail, you can stay to the right on the high route along the Santiago Trail, or take the left fork and head down the Egret Trail.  The Santiago Trail is the most popular route, but is a little too close to the backyards of the houses bordering the park for our tastes.  The Egret Trail creates a little more illusion of nature and wilderness, and takes you a little close to the reeds and riparian habitat of the Creek, but gets you to Irvine Park just as quickly.  They’re really only about 50-100 feet apart, with several unofficial connecting trails between them, so even if you start on one, you can switch to the other at several points along the way.

Once over the top of the dam, you can hang right underneath the other dam, or turn leftward down the Egret Trail. We prefer Egret, but they'll both get you the same place.

View down Egret Trail towards Irvine Regional Park.

Egret Trail and Santiago Trail are both very exposed, and can be quite miserable in the summer or even in the middle of any particularly warm day, but in the morning, or on a cooler day, it is very pleasant.  In the spring, there are great wildflowers along this stretch, but it is admittedly brown in the late summer, fall, and early winter, like when we made this particular hike.  About 1/4 mile past the split, you’ll come to a shaded structure (that looks like it should have a picnic table or something, but didn’t on this particular day) right at the junction with another trail.  You could take Willow Trail here to get to Irvine Regional Park, but our preference is to repeat trails as little as possible, so in the interests of making this more of a loop, we will continue on Egret and return on Willow.

Shelter at the junction of Egret Trail and Willow Trail. Stay right.

You're never really far from homes along this stretch.

The trees on the horizon are the border of Irvine Regional Park.

Not too long after you hit the 2 mile mark, you’ll hit a dead end at a trail that runs perpendicular to Egret and Santiago Trails right at the edge of Irvine Regional Park.  There is a whole line of trees here at the beginning of the park, so it is really impossible to miss.  Turn right to re-connect with Santiago Trail and then turn left to head into the park.  You’ll find yourself at the southwest corner of Irvine Regional Park, not too far from the main entrance, and possibly more importantly, not far from the restrooms (flush toilets!).

The perpendicular trail at the end. Turn right and follow to the left. That cut to the right up ahead is Santiago Trail.

The skinny one to the left heads right to Irvine Park. The fire road on the right doesn't.

Irvine Regional Park!

If you want to explore Irvine Regional Park, there is a lot there, especially for kids.  You can visit the small zoo, get a hot dog or ice cream at the concession stands, ride the miniature railroad, check out the Spanish-American War Memorial, or just hang out at one of the many picnic tables to eat your lunch.  We just sat down in the shade and lush grass at the corner of the park, watered the dog, and ate our beef jerky and trail mix before heading back to Santiago Oaks.

Holly enjoying the cool grass. Restrooms are in the distance.

A little cross trail at the west end of the park, heading toward Willow Trail.

The Willow Trail junction on the left.

There are a couple ways to return to that trail at the edge of the park (really a continuation of Santiago Oaks Trail, if you look at the map), but from there, you can connect to the Willow Trail, which is actually our favorite of the four different options to return to Santiago Oaks.  Willow trail is more shaded than Santiago and Egret, and more direct than Roadrunner, which we’ll discuss when we write up the longer trans-park hike another time.  This trail has much more of a riparian feel, and when there is water in Santiago Creek, you will regularly see running water alongside the trail.

You'd think the Willow Trail sign would be actually at the junction, rather than near the junction, but no.

Beginning of the Willow Trail.

Willow Trail. More shaded than Egret or Santiago.

In a wetter season, there would be water down there on the left.

The end of the Willow Trail. In a really wet season this may be impassable. You might want to ask first...

Back at the shelter where Willow rejoins Egret. A picnic table would be nice here!

Approximately 1 mile from Irvine Regional Park, Willow Trail reconnects with Egret Trail, right at the covered shelter I mentioned earlier.  Turn right and continue down Egret Trail back towards the dam.  At the top of the dam, just before you hit the corral that connects you to Pony Trail, there is another informational sign and a junction with Santiago Trail to the right.  Take Santiago to the right here, and head down towards the creek.

Returning towards the dam and Santiago Oaks Regional Park.

Top of the dam heading back. The small trail back is just to the left of the chain link fence.

Turn right before the corral, taking Santiago Trail to the creek.

Scary warning signs. Ignore them.

You may pass a series of warning signs before coming to the edge of the creek itself.  We’ve been here during a wet, rainy year, when this crossing was basically impossible, but usually it is pretty easy.  If you are a particularly conscientious/prepared hiker, you might ask at the entrance of Santiago Oaks Park whether the Santiago Creek crossing in front of the dam is open or not, but if it isn’t, you don’t have far to backtrack to get to the Pony Trail creek crossing.  And if you can’t get across either, then you never made it to Irvine Park in the first place, did you?

The creek is usually crossable.

Irvine Regional Park

But sometimes not. If it looks like this, heed the warning signs!

Holly enjoying the cool water at the crossing.

These are the signs you would ignore coming from the other side.

Santiago Trail on the way back to the parking lot.

If you stay on the Santiago Creek Trail, you will rejoin the junction with Pony Trail in about a half mile.  From here, you will repeat the beginning of the trail for the last third of a mile or so to re-cross Santiago Creek at the concrete steps and get back to your vehicle.

Back in the shaded part! It's nice to end in the shade, especially on a warm day.

So this isn’t really technically a loop trail, or even a lollipop trail, but by using our route choices you only repeat the third of a mile at the beginning and end (the best part, btw), and a half mile in the middle between the top of the dam and the Egret-Willow split.  At just over 5 miles and very little elevation gain, it is a really nice mid-range hike that is really easy to get to, and provides the illusion of getting out of town, without really having to drive very far at all.

View Santiago to Irvine Inside Park Loop in a larger map

Elevation profile. Click through for clearer view.


  1. J says

    Be careful for pets drinking the water, guardia and leptospirosis bacteria in run off and stale water. Bring bottled water for pets.

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