San Carlos Falls

Yona / Asan / Nimitz Hill, Guam, Micronesia

About San Carlos Falls


Hiking Distance: 4 miles round trip; requires steep rope-aided slopes and riverbed scrambling
Suggested Time: about 4 hours

Date first visited: 2022-11-23
Date last visited: 2022-11-23

Waterfall Latitude: 13.44259
Waterfall Longitude: 144.7326

Waterfall Safety and Common Sense

San Carlos Falls was a moderately-sized 40ft plunging waterfall spilling into a very inviting plunge pool that was quite clear and full of fish.

In fact, this was said to be my guide’s favorite waterfall hike on Guam, and we even encountered a large group of military personnel who used their off-day to enjoy a swim here as well.

San_Carlos_Falls_122_11222022 - San Carlos Falls
San Carlos Falls

That said, the military folks that we met have told me that this place is typically not this busy, especially since it was a pre-Thanksgiving Day holiday for them.

Speaking of swimming, an excursion to the San Carlos Falls also can be extended to include an attractive cascade and plunge pool, which was informally referred to as the San Carlos Swimming Hole.

Curiously enough, the San Carlos Swimming Hole is on the Lonfit River, but the San Carlos Falls is on a seasonal tributary feeding the river, which also contains the Batan Falls (or Bijou Bataan Falls).

Unlike some of the other waterfalls that I’ve witnessed in my short time visiting Guam, I noticed that the farther away from “civilization” you are, the more clear the water.

San_Carlos_Falls_102_11222022 - Context of the attractive and idyllic San Carlos Swimming Hole
Context of the attractive and idyllic San Carlos Swimming Hole

In the case of these waterfalls and swimming holes, we did have to go on a somewhat moderate to difficult hike from Nimitz Hill in the southern center of the island, which took us a fairly leisurely 4 hours to go about 4 miles or so.

Of course, I should caveat that time duration because this included a few rest breaks, a lunch break, and some time to swim in front of San Carlos Falls.

On the day of our visit (the day before Thanksgiving in November 2022), we experienced both the San Carlos Falls and the San Carlos Swim Hole in a bit of a lollipop-shaped loop route, which is how I’ll delve into the rest of this write-up.

Trail Description – Hiking Towards The Lonfit River

From the trailhead parking near Nimitz Hill (see directions below), we essentially followed a series of roads (both paved and muddy 4wd tracks).

San_Carlos_Falls_008_11222022 - The hiking group joining up with a muddy 4wd track flanked by power lines early on in the San Carlos Falls hike from Nimitz Hill
The hiking group joining up with a muddy 4wd track flanked by power lines early on in the San Carlos Falls hike from Nimitz Hill

It began by following Turner Road until the first 4wd turnoff on the left, where we then took a brief interlude towards a different 4wd track that followed some power lines.

Next, we followed this power line flanked 4wd track for around 600-700ft to the next 4wd track on the right.

In my experience, this was the muddiest of the 4wd tracks, but it was only in the northern part of its 1/4-mile stretch.

Then, we went left onto a paved road that my map calls the US Naval Station Nimitz Hill, which had a trench being dug out alongside the road during our visit.

San_Carlos_Falls_016_11222022 - The group negotiating perhaps the muddiest part of the 4wd tracks leading us closer to the San Carlos Falls hike from Nimitz Hill
The group negotiating perhaps the muddiest part of the 4wd tracks leading us closer to the San Carlos Falls hike from Nimitz Hill

We continued east for another 1/4-mile before reaching a makeshift bridge going over the trench to our right (so there’s no guarantee this bridge will be there once this work is done).

From there, we followed yet another road for the next 1/4-mile, which meandered towards larger power pylons until ultimately terminating at the base of one such pylon.

Right behind this pylon, the track then finally became grassy and more naturesque as we undulated on some ridges flanked by swordgrass while also offering some views both to the east and to the west.

Towards the east, we saw the start of a watershed system before dropping off in a pair of gullies, which my guide said that the Batan Falls was.

San_Carlos_Falls_024_11222022 - The hiking group following a paved road alongside more power lines and a trench being dug up for some pipeline work
The hiking group following a paved road alongside more power lines and a trench being dug up for some pipeline work

The waterfall itself wasn’t that visible during our visit due to the thickness of the vegetation combined with lower waterflow.

Meanwhile, looking in the opposite direction to the west, we noticed the radio towers sitting atop Mt Alutom, which was where I had hiked to both Upper Sigua Falls and Maguagua Falls.

Continuing in a southeasterly direction, the track eventually dropped towards a grove of palm trees where we then followed a fork in the faint trail to our right.

This fork ultimately marked the beginning and end of a looping route that would encompass both the San Carlos Falls and the San Carlos Swimming Hole.

San_Carlos_Falls_062_11222022 - Looking towards the drainage where Batan Falls was located, and this is one of the feeder streams that ultimately drain towards San Carlos Falls
Looking towards the drainage where Batan Falls was located, and this is one of the feeder streams that ultimately drain towards San Carlos Falls

According to my GPS logs, it took roughly 1.5 miles from the trailhead to reach this decision point.

Trail Description – The Loop Encompassing San Carlos Falls and San Carlos Swim Hole

Our group ultimately opted to do the looping part of this trek in a counterclockwise direction (though the military guys we met ended up doing this loop in a clockwise manner).

So this trail description is happening in this counterclockwise direction, which is contrary to the suggested route described in “The Best Tracks on Guam” book (advocating for an out-and-back route).

Regardless, it didn’t take long on the fork that we took as we went through some swordgrass before the path descended steeply down a muddy (i.e. very slippery) slope with some rope tied to some trees for leverage.

San_Carlos_Falls_064_11222022 - The group following a ridge before descending towards the drainages involved in the San Carlos Falls and San Carlos Swimming Hole landmarks
The group following a ridge before descending towards the drainages involved in the San Carlos Falls and San Carlos Swimming Hole landmarks

This rope-aided muddy slope was one of the reasons why this hike is considered “difficult”, and like other undeveloped hikes in Guam, you’ll definitely want to be wearing long-sleeved shirts, long pants, and gloves.

After carefully making our way down to the bottom of this decline, we then found ourselves on the banks of the Lonfit River right above the small waterfall spilling into the San Carlos Swimming Hole.

The river here was notable because there were lots of tadpole-looking “dots” in the calmer parts of the river.

Anyways, the river was also shallow enough to be able to cross the stream without getting Gore-tex boots wet, and we then carefully used rope to descend alongside the far western side of the falls.

San_Carlos_Falls_081_11222022 - Descending a steep and very muddy slope with the aid of rope as we made our way down to the Lonfit River and the San Carlos Swimming Hole
Descending a steep and very muddy slope with the aid of rope as we made our way down to the Lonfit River and the San Carlos Swimming Hole

Once at the bottom, we then scrambled towards the front of the plunge pool, where we then started a riverbank scramble along the Lonfit River downstream for the next 700ft.

Eventually, our scrambling along the north side of the Lonfit River brought up to a confluence with a tributary stream, where we then followed the west side of its banks upstream for the final 700ft or so.

Along this stretch, there a bit more stream walking or at least walking on very slippery rocky stream beds, which was another part of this hike that made it more difficult.

At least we approached the San Carlos Falls and its inviting plunge pool without much elevation change, and it was perhaps the most suitable way to approach the falls.

San_Carlos_Falls_115_11222022 - The group stream scrambling upstream towards San Carlos Falls
The group stream scrambling upstream towards San Carlos Falls

When we arrived, we saw a large group of military folks on their off day either already in the plunge pool or still climbing down a steep slope alongside the east side of the falls itself.

As for the plunge pool fronting San Carlos Falls, I noticed that the water was very clear, but I also noticed that there was a pretty large group of fish as well.

Anyways, that slope with the rope turned out to be the route that we would take on the way out.

Therefore, it probably didn’t matter which way we went (either clockwise or counterclockwise like we did) as far as difficulty was concerned.

San_Carlos_Falls_148_11222022 - Context of the slippery stream scramble as we made our way upstream from the San Carlos Falls on the way out
Context of the slippery stream scramble as we made our way upstream from the San Carlos Falls on the way out

However, I did appreciate the counterclockwise approach that we took because of our approach to the San Carlos Falls itself.

So after having our fill of the San Carlos Falls, we then climbed up the rope-assisted incline eventually going higher than the tributary stream before dropping back down to it right at the brink of the San Carlos Falls itself.

From there, we continued stream scrambling (on slippery bedrock surfaces) for about 400ft or so before reaching a steep incline that also involved the use of rope to get out of the tributary’s drainage.

Our guide mentioned to me that had we continued stream scrambling further upstream, we’d eventually reach the Batan Falls.

Anyways, after about 200-300ft or so, we’d eventually return to the grassy slope, where we then went back the way we came along a series that ridges and roads that we had taken on the way in.

San_Carlos_Falls_150_11222022 - The group leaving the stream and making the steep rope-aided climb back up to the grassy ridges and 4wd tracks that we had come in upon as we were leaving San Carlos Falls
The group leaving the stream and making the steep rope-aided climb back up to the grassy ridges and 4wd tracks that we had come in upon as we were leaving San Carlos Falls

Although this hike was pretty much a fairly difficult 1/2-day excursion, I had to say that it probably felt the most rewarding when you consider the pain versus pleasure equation, especially compared to say Tak’hilo Falls.

Authorities

San Carlos Falls resides near Nimitz Hill in the village of Yona and Asan, Guam. It may be administered by the Guam Department of Agriculture. For information or inquiries about the area as well as current conditions, you can try visiting this website.

San_Carlos_Falls_005_iPhone_11232022 - Getting geared up at the San Carlos Falls Trailhead for the hike to get there
San_Carlos_Falls_002_11222022 - The group following Turner Road at the start of the hike to San Carlos Falls
San_Carlos_Falls_003_11222022 - Looking back at the trailhead parking for San Carlos Falls
San_Carlos_Falls_004_11222022 - The first 4wd track leaving Turner Road as we made our way towards San Carlos Falls
San_Carlos_Falls_005_11222022 - The grouop following the initial 4wd track after leaving Turner Road
San_Carlos_Falls_009_11222022 - The group trying to avoid some muddy puddles on the next 4wd track following some power lines on the way to San Carlos Falls
San_Carlos_Falls_013_11222022 - The group hanging a right at the next 4wd track, which was also getting to the muddiest part
San_Carlos_Falls_014_11222022 - The group navigating through a fairly saturated stretch of standing water and mud on the 4wd track early on in the San Carlos Falls hike
San_Carlos_Falls_015_11222022 - The group getting through the muddiest stretch of the 4wd tracks that we took on the way to San Carlos Falls
San_Carlos_Falls_018_11222022 - The group trying to get into the swordgrass to avoid the worst of the stagnant water and mud on the 4wd track en route to San Carlos Falls
San_Carlos_Falls_020_11222022 - The group of hikers getting past the muddiest part of the 4wd track as we were slightly climbing and still following some power lines en route to San Carlos Falls
San_Carlos_Falls_022_11222022 - Approaching some structure vehicles that were working on some trench work next to the next road that we walked on en route to San Carlos Falls
San_Carlos_Falls_027_11222022 - The group following a paved road alongside a trench as we made our way towards San Carlos Falls
San_Carlos_Falls_029_11222022 - The group going across a makeshift bridge over a trench as we left the paved road and headed closer to the San Carlos Falls
San_Carlos_Falls_030_11222022 - The hiking group continuing on a different paved part of the road on the way towards San Carlos Falls after leaving the road flanked by a trench
San_Carlos_Falls_033_11222022 - Looking from the San Carlos Falls Trail towards the radio towers atop Mt Alutom
San_Carlos_Falls_034_11222022 - The group continuing to follow the paved road on the way to San Carlos Falls
San_Carlos_Falls_035_11222022 - The group continuing on the gently descending road leading us closer to the power pylons in the distance en route to San Carlos Falls
San_Carlos_Falls_037_11222022 - The group now following the paved road, which was following the base of these steel power pylons en route to San Carlos Falls
San_Carlos_Falls_039_11222022 - Zoomed in look at what appeared to be an ant farm seen on the vegetation next to the partially paved road by the power pylons en route to San Carlos Falls
San_Carlos_Falls_041_11222022 - The group starting to deviate from the paved road beneath this power pylon as we were now on the legitimate hiking part of San Carlos Falls
San_Carlos_Falls_042_11222022 - Looking back at the power pylons that we had walked besides on the paved part of the road shortly after we left it to hike on grass en route to San Carlos Falls
San_Carlos_Falls_044_11222022 - The group now hiking on trampled grass in between the waist-high vegetation en route to San Carlos Falls
San_Carlos_Falls_046_11222022 - The group descending a fairly slippery (loose gravel) part of the course leading us down to San Carlos Falls
San_Carlos_Falls_049_11222022 - The group continuing to follow trampled grass as we followed a ridge en route to the San Carlos Falls
San_Carlos_Falls_051_11222022 - The group descending on a red dirt track flanked by some fairly tall swordgrass en route to San Carlos Falls
San_Carlos_Falls_053_11222022 - Context of some colored tape and the dirt track flanked by swordgrass en route to San Carlos Falls
San_Carlos_Falls_055_11222022 - An unmarked trail fork, where our guide knew to keep right instead of getting misled to the left on the way to San Carlos Falls
San_Carlos_Falls_056_11222022 - Another contextual look by the blue ribbon on the way down to San Carlos Falls
San_Carlos_Falls_057_11222022 - The group going through a fairly tall patch of swordgrass while still trying to follow the trampled path leading us closer to San Carlos Falls
San_Carlos_Falls_059_11222022 - The group still following the 4wd track as we briefly climbed to a mild ridge en route to the San Carlos Falls
San_Carlos_Falls_061_11222022 - Looking in the direction of Batan Falls from the San Carlos Falls route
San_Carlos_Falls_067_11222022 - Looking towards a fairly sizable grove of palm trees as we were descending towards the drainages responsible for San Carlos Falls and Swimming Hole
San_Carlos_Falls_070_11222022 - The group following a faint path on the way towards the Lonfit River as we did the lollipop-loop hike in an anticlockwise direction
San_Carlos_Falls_071_11222022 - The group continuing to follow a faint trampled grass path on the way to the Lonfit River during our hike to San Carlos Falls
San_Carlos_Falls_073_11222022 - The group continuing to navigate through some trampled grass on the way down to the Lonfit River
San_Carlos_Falls_075_11222022 - The trekking group now starting to descend a slippery and muddy track as we descended towards the Lonfit River in the distance
San_Carlos_Falls_076_11222022 - The group now encountering a steep and muddy rope-aided descent as we were getting even closer to the Lonfit River
San_Carlos_Falls_077_11222022 - Looking back up at some rope tied to a pole, which illustrated just how steep and slippery this descent to the Lonfit River was
San_Carlos_Falls_078_11222022 - The group negotiating more rope-aided muddy slopes on the way down to the Lonfit River
San_Carlos_Falls_082_11222022 - Looking back at the steep muddy slope that we had to descend upon in order to reach the Lonfit River
San_Carlos_Falls_083_11222022 - Another look at the steep and muddy slope leading us down to the Lonfit River as we did the lollipop-shaped route in a counterclockwise direction
San_Carlos_Falls_085_11222022 - Looking down at rope tied to the base of a tree near one of the final stretches of descending towards the Lonfit River en route to San Carlos Falls
San_Carlos_Falls_086_11222022 - Another look back up the steep rope-aided descending slope on the way down to the Lonfit River
San_Carlos_Falls_087_11222022 - Finally making it down to the Lonfit River right at the brink of the cascade spilling into the San Carlos Swimming Hole
San_Carlos_Falls_090_11222022 - Looking back upstream from the brink of the San Carlos Swimming Hole cascade as we took a break for a bit after all the steep descending that we did to get to this point
San_Carlos_Falls_092_11222022 - Looking across part of the cascade spilling into the San Carlos Swimming Hole
San_Carlos_Falls_008_iPhone_11232022 - Looking across the cascade spilling into the San Carlos Swimming Hole
San_Carlos_Falls_094_11222022 - Soo (sp?) taking a break at the brink of the cascade for the San Carlos Swimming Hole
San_Carlos_Falls_095_11222022 - Looking down into the shallow part of the Lonfit River, where we could clearly see lots of black dots with tails (likely tadpoles)
San_Carlos_Falls_096_11222022 - The group going across the Lonfit River to get below the San Carlos Swimming Hole cascade
San_Carlos_Falls_099_11222022 - Looking back across the full width of the San Carlos Swimming Hole Waterfall
San_Carlos_Falls_100_11222022 - The group waiting for Soo (sp?0 and I to get back across the Lonfit River to resume the downstream hiking towards San Carlos Falls
San_Carlos_Falls_103_11222022 - The group now navigating their way along the banks of the Lonfit River towards San Carlos Falls
San_Carlos_Falls_105_11222022 - Still trying to follow some colored ribbons on the way towards San Carlos Falls
San_Carlos_Falls_107_11222022 - The group continuing to follow the banks of the Lonfit River somewhere between San Carlos Swimming Hole and San Carlos Falls
San_Carlos_Falls_108_11222022 - More colorful ribbons along the banks of the Lonfit River to help make our experience a little easier
San_Carlos_Falls_111_11222022 - The group continuing to go through some swordgrass along the banks of the Lonfit River towards San Carlos Falls
San_Carlos_Falls_112_11222022 - The group now deviating from the Lonfit River and heading upstream towards the San Carlos Falls
San_Carlos_Falls_114_11222022 - The group making their way upstream alongside the clear water on the stream we were following towards San Carlos Falls
San_Carlos_Falls_116_11222022 - Looking up at one of the military guys here who was carefully descending rope to get down to the base of San Carlos Falls
San_Carlos_Falls_124_11222022 - Looking ahead at the festive context of San Carlos Falls and its inviting plunge pool
San_Carlos_Falls_132_11222022 - Context of some fishing swimming on the near side of the plunge pool before the San Carlos Falls
San_Carlos_Falls_010_iPhone_11232022 - Another contextual look at the very inviting scene to cool off before the San Carlos Falls
San_Carlos_Falls_135_11222022 - Looking up at the steep hill and some rope as we made our way out of the San Carlos Falls
San_Carlos_Falls_136_11222022 - After the steep climb out of San Carlos Falls, we then had to descend back down to the level of the creek above San Carlos Falls
San_Carlos_Falls_139_11222022 - Context of a fallen tree right across from the brink of San Carlos Falls
San_Carlos_Falls_143_11222022 - Looking precariously down over the brink of San Carlos Falls
San_Carlos_Falls_144_11222022 - Another look across the very brink of San Carlos Falls
San_Carlos_Falls_145_11222022 - After having had our fill of the brink of San Carlos Falls, we had to continue upstream on some fairly sketchy and slippery bedrock
San_Carlos_Falls_149_11222022 - The group continuing to push upstream as we looked for a way to get back out of the ravine
San_Carlos_Falls_152_11222022 - The group making the very steep rope-aided ascent to get out of the drainage and back onto the grassy ridges
San_Carlos_Falls_153_11222022 - The group finally ascending past the worst of the rope-aided slopes and now traversing through the familiar grassy terrain
San_Carlos_Falls_156_11222022 - The group still had to climb up to the top of this incline
San_Carlos_Falls_158_11222022 - Closer look at what appeared to be a noni fruit on the way back up from the San Carlos Falls drainage
San_Carlos_Falls_159_11222022 - The group now back on the grassy ridge as we made our way back out from the San Carlos Falls
San_Carlos_Falls_162_11222022 - The group continuing to follow the partially red dirt track flanked by some wildflowers blooming by us on the way back to the San Carlos Falls trailhead
San_Carlos_Falls_164_11222022 - The group approaching the power pylons in the distance on our way back to the trailhead for San Carlos Falls
San_Carlos_Falls_168_11222022 - The group ascending on the somewhat paved road on the way back from San Carlos Falls
San_Carlos_Falls_170_11222022 - The group making it back to the road alongside the ditch as we made our way towards the trailhead San Carlos Falls
San_Carlos_Falls_172_11222022 - Soo (sp?) making his way back through the messy muddy stretches of the 4wd track on the return hike towards the trailhead for San Carlos Falls
San_Carlos_Falls_173_11222022 - Making it back to the power pole-lined 4wd track after getting past the worst of the muddiest stretches on the way back from San Carlos Falls
San_Carlos_Falls_174_11222022 - Continuing to follow this powerline flanked red dirt track on the way back to the trailhead for San Carlos Falls
San_Carlos_Falls_175_11222022 - Finally back on Turner Road making our way to the trailhead or car park for the San Carlos Falls
San_Carlos_Falls_176_11222022 - When we returned to the trailhead for San Carlos Falls, we couldn't believe how quickly the lot emptied out, which suggested that the military folks had already left this place


The trailhead for San Carlos Falls sits a short distance to the west (or southwest) of Nimitz Hill near the intersection of Larson Road and Turner Road (both by the Route 6).

Even though the trailhead parking was not officially signed, there seemed to be a few large clearings flanking Turner Road making it seem like a pretty obvious spot to start a hike (though not necessarily obvious to start the San Carlos Falls hike).

San_Carlos_Falls_002_iPhone_11232022 - Following Marine Corps. Drive (Hwy 1) towards Hwy 6 and Nimitz Hill en route to the San Carlos Falls hike
Following Marine Corps. Drive (Hwy 1) towards Hwy 6 and Nimitz Hill en route to the San Carlos Falls hike

To get here from Tumon Bay, we’d drive west on Marine Corps. Drive (Hwy 1) for a little over 8km to its junction with Route 6.

Turning left onto Route 6, we then drove about 5km towards Larson Road (not far past Nimitz Hill) before turning left onto that road.

Then, at the T-intersection between Larson Road and Turner Road was the parking for the San Carlos Falls hike.

Overall, this drive took us under 30 minutes.

San_Carlos_Falls_001_11222022 - Context of Turner Road and the parking situation for the San Carlos Falls hike
Context of Turner Road and the parking situation for the San Carlos Falls hike

Finally, for geographical context, Yona was about 18km (under 30 minutes drive) north of Inarajan, about 19km (under 30 minutes drive) south of Tamuning, and 20km (about 30 minutes drive) south of Tumon Bay.

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Brief left to right sweep of a cascade and swimming hole on the way to San Carlos Falls


Direct back and forth sweep of the swimming hole cascade near San Carlos Falls


Downstream to upstream sweep of people swimming and chilling out at San Carlos Falls


Brief sweep showing the falls and some fish in the plunge pool


Upstream to downstream sweep from the very brink of San Carlos Falls

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Tagged with: nimitz hill, yona, asan, guam, waterfall, hike, muddy, rope, swimming, swordgrass, palm, neti, powerlines, lonfit river, san carlos swimming hole



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Johnny Cheng

About Johnny Cheng

Johnny Cheng is the founder of the World of Waterfalls and author of the award-winning A Guide to New Zealand Waterfalls. Over the last 2 decades, he has visited thousands of waterfalls in over 40 countries around the world and nearly 40 states in the USA.
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