The ideal weather in Moab is during spring and fall, but many people only have the option to travel in summer, when heat and sun can be oppressive in the rocky desert. To maximize summer fun in Moab and minimize exposure, it is best to do half-day trips that start early and end before temperatures get too intense. But then what to do in the afternoon?
Easy! Escape to a refreshing oasis of water and shade. Moab's indulgent swimming holes remained a "locals only" secret for a long time, but these enticing gems couldn't stay underground forever. The obvious water near Moab is the silty Colorado River, but a leisure-seeker's treasure is the clear and cold Mill Creek, tucked away in a canyon just outside of Moab.
Mill Creek and North Fork of Mill Creek are perennial streams flowing from the alpine slopes of the La Sal Mountains. The walled-in forks where they meet would be a spectacular hiking destination as a sandstone gorge even without the streams, but the amenity of water makes it truly irresistible. Babbling riffles and cascades feed a few calm pools that make perfect swimming holes.
The easiest pool to get to is right by the parking lot, and it comes with a nice, albeit artificial, waterfall. Simply walk a few hundred feet from your car and scramble down the rocks to a series of shallow pools below the falls, which pour over top of an old powerhouse dam.
This spot makes for a quick dip, but the real goods take a little more effort. By following the trail past the dam and into the canyon for about a mile, you will find a natural waterfall that pours into a built-up pool that is secluded in an amphitheater of sandstone. The trail to get here is flat and shady, but it crosses the creek quite a few times in ankle-deep water. Follow the signed trail up North Fork Mill Creek rather than the side trail (to the right) that bushwhacks up Mill Creek Canyon proper.
Once at the pool, stretch out in the sun or relax in the shade, either on the rocks or in the water. This paradise is worth enjoying for the whole afternoon, so bring a picnic and some drinks. You will likely meet people from all over, locals and tourists alike, families and solo travelers. The pool is big enough for everyone to comfortably sit, wade, or swim around. Cliff jumping is an option, but the deep spots are usually no more than 7 feet, so use extreme caution.
The swimming holes are not the only attraction here, either. The canyon walls display Native American petroglyphs. To find them, look closely at overhung panels with darker red coloration, the special canvases that ancient artists preferred. There are younger relics as well. Caves near the mouth of the canyon were used by settlers for shelter and storage, as evidenced by constructed rock walls.
The trail even continues past Mill Creek Falls. Further up canyon, you will find seclusion among the reeds and cottonwoods, where several more swimming holes and small cascades await exploration. You can make a full day by hiking the upper reach of North Fork Mill Creek. Look around for wildlife like deer and even beaver that thrive in this precious desert oasis.
Note that this area suffers from intense user pressure, and overcrowding is a serious issue here. Parking at the trailhead is simply inadequate given the area's popularity, and many choose to illegally park along the road and in front of nearby residences. Don't be one of these people. Areas like this close quickly if visitors become disrespectful to the land and its residents and neighbors. If no legal parking remains, come back at another time. Plan to visit early in the day or mid-week to avoid heavy crowds and help dissipate your imact, and always practice Leave No Trace.
Swimming holes and cliff jumping can be extremely dangerous and unpredictable outdoor activities that pose significant risks regarding personal safety. Changing water levels, unseen rocks, and river bottoms that have shifted with currents and seasonal weather can turn a well-known jumping area into a serious hazard. Prior to engaging in these activities, extensively scout the current conditions, and understand the risks involved with serious injury and the logistical challenges of evacuation from the water so you can make safe decisions.