Los Prieto Falls on El Yunque’s South Side
Posted on Apr 18th, 2010 by Gwenn • Updated on Nov 3rd, 2011
The El Yunque National Forest covers 28000 acres, and much of it is protected as wilderness areas. Ray and I are always looking for new trails to hike and, of course, elusive waterfalls. We recently went to the south side of the rain forest in search of Los Prieto Falls. We found a great hike and beautiful set of waterfalls, too!
Some Background
We originally did this hike about 5 years ago with Robin Phillips as our guide. We remembered it being easy enough, so when some friends (Lori and Butch) from the States came down to visit, we set off to find the falls again, sans guide.
I really don’t know what I should call this hike: Los Prieto Falls Hike, the Water Line Hike, or the Forbidden Hike. The hike actually follows a forbidden trail, along a water supply pipe to Los Prieto Falls.
Getting to the Trail Head
(Updated 3/11 since they opened the Picnic area) We drove up South Road 191 until you get to a gate (it is occasionally open now), but you will notice a nice natural pool. There is a little trail on the left side of the road, before the bridge, that leads up to a natural pool in the Cubuy River. There’s also a pretty, little waterfall to see here. We’ve been here on summer weekends and it gets really crowded with people swimming and having picnics near the river.
If the gates are open, drive up to the parking area, if not, park and walk in. You then can keep going until you get to the new Rio Sabana Recreation Area, complete with a big parking lot, a number of picnic pavilions, and restrooms.
In this area, there is a large natural pool to the left of the road in the Sabana River. Also, the trail head for the Rio Sabana trail can be found uphill to the right of the picnic pavilions.
To the right of the road, near the entrance to the parking lot, there is a large gate across a dirt trail and a sign from the Puerto Rico Electric Authority (AEE, by their Spanish initials) stating that entry to the trail is prohibited and it is to be used by authorized individuals only. Toward the back of the parking lot, on the right hand side, we found a small path that leads down to the AEE trail.
Remember, the AEE prohibits access to this trail, which is used to maintain parts of the Rio Blanco Hydroelectric Project. If you use this trail, you are doing it at your own risk.
On the Water Line Trail
This trail is amazingly well-maintained (I guess because it is still in use). They constructed the water line to move the water from the upper forest rivers to a hydroelectric generating station in the town of Naguabo, located at the base of El Yunque.
We walked along the path, following the water pipe, with the Sabana River below us and to the right. There are some great views along the way of rivers and waterfalls, and views to the east coast of Puerto Rico. At about the half-way point, a small set of train tracks appeared out of the forest floor alongside the pipe. It’s my understanding that the waterline workers used small trains to move building and maintenance supplies along this trail.
This forest walk is beautiful. Lots of banana plants, flowering heliconias, and various trees like giant fern trees, Sierra Palms and Tabonuco trees, all of which made me think that I had somehow been transported back in time. I almost expected to see dinosaurs whenever we turned a corner!
We found some wild raspberries to eat along the way, too.
Most of the trail was in the shade, but there were spots that were in full sun. A hat or sunglasses would have come in handy.
The trail is easy and relatively flat — we only had a 400-foot rise in elevation during the 2½-mile hike. There were a few places where we had to scramble up or down some rocks, and some muddy areas. We went under the pipe crossing at two ravines and used the AEE catwalk to cross a dam at the water reservoir on the Icacos River.
I would rate this as an easy-to-moderate hike. Our group ranged from 44 to 64 years old, and we all did fine. We met a young family (with a 6 year old) at the start of the trail and saw them later on our way back. They didn’t make it to the waterfall, but they were having a great day in the forest.

At Los Prieto Falls
In the summer of 2010, we had so much rain it washed out the reservoir. It also seems to have changed the flow at the falls (they are less impressive now).
According to our GPS, it was ¾ miles from our car to the trail head and another 1¾ miles on the trail — for a total for 2½ miles from the car to the waterfall. The waterfall is located near the intersection of the Sabana River and the Prieto River.
Once at the waterfall, we found some flat concrete near the base of the falls, where we sat and had our picnic lunch.
The lower falls were nice and, due to a recent rain, pretty big — a lot more water going over the falls than I remember from our earlier trip. I would guess that this lower waterfall is about 30-feet tall.
To the left of the lower falls, there is an old metal ladder that is chained off — I assume to keep people from using it. The upper waterfall we found to be beautiful and even bigger than the lower falls — maybe 50 feet tall. The views from the base of the upper falls are really spectacular!
The trail continues about ½ mile more past the waterfall. It eventually ends at a flat area on the edge of the earth — OK … that’s a bit dramatic. But there are more great views from the edge of the cliff where the trail ends. We didn’t didn’t get an early enough start to hike that second leg of this trail on this day. We’ll go back and hike all the way to the end some time in the future.
After spending time at the waterfall, we turned around and re-traced are steps along the trail and back to our car. At the end of the day, we had a really nice 5 mile hike and a bunch of great photos!
Details
No swimming or playing is allowed in the water along this trail. The AEE uses the rivers and reservoir in operating the hydroelectric generating station. There are high-suction water intakes and there are big orange warning signs all over the place. Also, I assume that the water reservoir dam is controlled by a timer or something. When we passed the dam on our way to the waterfall, there was no water flowing over the dam. On our way back, there was a bunch of water flowing over the dam. This could cause sudden and unexpected flooding in the lower rivers and streams.
This hike took us about 1 hour each way.

Wear appropriate shoes (no flip-flops!). Ray and I wore hiking shoes. Our friends wore sneakers, which worked out fine. The trail can be muddy and slippery. Bring plenty of water. Rain gear might help — it is a rain forest, after all!
From the north-east, take Route 53 south to Exit 22. Take Route 31 to Road 191 (Route 31 turns to the left and you go straight for Road 191). Follow 191 to the left across a large cement bridge and keep going up, until the end. We parked along the road.
Use this map to locate places mentioned in this article. You can click on a placemark to view the GPS coordinates for that place.































Hello!
Just found this on the internet:
The new Rio Sabana Recreation Area, located at PR road 191, Km 2.0 in Naguabo, will officially open for the public this summer commencing on Saturday, June 4 thru August 15th from 9:00 am – 5:00 pm and will be opened on weekends throughout the year from Oct.1 to May 31 during the same hours. Recreation Area will be closed during the month of September.
PS: I love your site!!!!
Comment by Gladys on May 11th, 2011 at 11:25 pmGladys- I hope you are right, but I would not put too much faith in that notice. The gate was supposed to be open on weekends the last 2 times we went, but it was locked and we had to park outside and walk in.
Comment by Gwenn on June 13th, 2011 at 8:33 am