A Stargazer's Guide to Lake Arrowhead
The drive up to Lake Arrowhead is a unique one. Highway 18 is part of what's known as the Rim of the World Scenic Byway. Look out over the ridge that the road traverses, and you really will feel like you've traveled to very edge of the world itself. When a trip starts with a view this great, imagine what the night sky must look like.
Lake Arrowhead is the most accessible mountain retreat for much of Southern California. With that status also comes some of the most accessible dark skies in this part of the state. Only about two hours away from Los Angeles, even closer to the Inland Empire cities of Redlands and San Bernardino, it's the perfect place for a break from the light and air pollution of the city. It's close enough to escape to even for just one night. At an elevation of about mile above sea level (5,174 feet, to be exact) and outside of the city, Lake Arrowhead boasts a striking night sky
A view of Comet Tsuchinshan–ATLAS from the Rim of the World. This image clearly shows how Lake Arrowhead is physically above the pollution of the city, as that layer of haze at the bottom is smog.
Escape the Light Pollution
As a rural mountain community, Lake Arrowhead has less light pollution than that seen in the city. While not as dark as some dark sky destinations, such as Big Bear, Lake Arrowhead still has a respectable dark sky worth the trip for a stargazer. On the Bortle Scale, Lake Arrowhead tends to rate from a 5 to a 5.9, depending on the location. The Bortle Scale, named for John E. Bortle who created it in in 2001, is a nine-level scale that measures how much light pollution is washing out the night sky in a given location.
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Bortle 1: Absolute, pristine darkness. The kind of sky where the Milky Way is so bright it actually casts a shadow on the ground.
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Bortle 9: Inner-city skies. You might see the Moon and maybe some of the brightest stars, but that’s about it.
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If you want to learn more about light pollution, check out my article on the topic.
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Lake Arrowhead proper tends to be around 5.5 to 5.8, depending on how close you are to major sources of outdoor lights. However, once you travel outside of the inhabited areas, you'll push that number down closer to 5.
A light pollution map of the San Bernardino Mountains from lightpollutionmap.app. The white is the completely light-polluted city of San Bernardino, while the red is latent light pollution from the city spreading into the mountains, and the green is where the sky starts to get dark again.
For the darkest areas of Lake Arrowhead, you'll want to travel to its north end, where there is little infrastructure and the mountain is between you and the light pollution of San Bernardino. Alternatively, if you continue down Highway 18 past Running Springs, you'll also find yourself in a far darker environment.
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In theory, you could stargaze right on the Rim of the World Highway. The view is unobstructed, and even the city lights below don't completely ruin the sky. Many would even enjoy the view of the sparkling city lights stretching out towards the horizon. However, note that passing cars with headlight could lessen the experience. We'll further discuss potential places to stargaze later.
A Mile-High Advantage
Space is generally considered to begin about 62 miles above sea level. Compared to that, Lake Arrowhead's mile high altitude may not sound that impressive, but it actually makes a significant difference when stargazing.
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When peering into space, astronomers have to contend with atmosphere. While air might seem transparent, if you take 62 miles of it, it becomes a problem. The atmosphere and its turbulent motion can distort the light of the stars, making them difficult to see clearly. However, the worst of the distortions is caused by the air, moisture, and pollutants at the very bottom. With that in mind, being a mile up suddenly becomes a major advantage.
The thick, heavy air filled with humidity, dust, and marine layer clouds is an obstacle that light from stars has to contend with on its trip down to sea level. This causes atmospheric extinction, where the light of fainter stars is scattered and absorbed before it ever reaches your eyes.
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As a high elevation desert mountain, Lake Arrowhead has air that is simultaneously dry and thin. This makes for a much clearer path that doesn't scatter the light of stars anywhere near as much as at sea level.
For proof of this atmospheric distortion, all you have to do is watch a star twinkle. While twinkling is a well-known feature of stars, it's actually a hurdle for an astronomer. Scintillation, as it's known scientifically, and is caused by light passing through turbulent layers of warm and cold air. It prevents a clear and crisp image of the stars.
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Lake Arrowhead's elevation means the mountain experiences good seeing conditions with minimal twinkling. While the stars will still twinkle, they are able to provide a far more steady and crisp point of light in the sky for you to enjoy.
Lake Arrowhead Stargazing Tips
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Find an open area. Finding the right place to stargaze in the mountains can be a challenge. Trees, hills, and buildings can get in the way of the sky. The best stargazing areas have a wide open sky. Scout for open locations during the day, if you can.
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Dress in layers. Mountain temperatures can vary, even in the summer. Be ready for cooler temperatures during night.
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Drink plenty of water. The thin mountain air may be helpful for astronomy, but also causes your body to lose water faster than normal, leading to dehydration if you'ren ot careful. Staying hydrated also helps your eyes see better.
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Give your eyes a chance to adjust. Your eyes can take up to 30 minutes to fully adapt to the darkness. Faint light, like that of stars, can be difficult to properly see without letting your eyes first adjust to the dark.
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Use a red light. Just one quick flash of a bright white light from a traditional flashlight can ruin your night visions and require your eyes readjust. Red lights don't ruin night vision, so you can use them to see where you're going while keeping your view of the stars in tact.
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Download a sky map app. There are many apps available for free that will not only tell you where to look in the night sky, but also what you're looking at. The apps are able to use your phone's compass and gyroscope to determine what celestial objects you're pointing it at.
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Consider binoculars. Even if you don't have a telescope, binoculars can be great for stargazing too.
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Check the Moon phase. If it's a full moon or close to it, the light from the Moon can make it harder to see the stars. New moons, and the week leading up to and after them, are the best times to stargaze.
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If you want a more detailed guide to stargazing, read my article on the topic.
Places to Stargaze in Lake Arrowhead
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Strawberry Peak: A location so well known for its view, it even has a fire lookout tower. The peak offers a stunning panoramic view.
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Highway 173: On the north end of the mountain, the 173 leaves the inhabited area and is away from light pollution. With a chaparral environment, there's less trees to block the sky. If you're up for a short hike, for a good view, there's the Pinnacles OHV Staging Area.
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The Lake: Lake Arrowhead is a private lake, but if you have lake rights, then the lake offers an unobstructed view of the sky.
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Highway 18: As stated previously, stopping along the 18 is an option. Just know that headlights of passing cars will ruin your night vision. For a slightly better experience, stop somewhere like Crest Park or Switzer Park.
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Keller Peak: Like Strawberry Peak, the view is so great it used to have a fire lookout tower. This is Amid the Star's tour location of choice.
If you're really looking for the best stargazing Lake Arrowhead has to offer, then consider booking a stargazing tour with Amid the Stars. You'll get access to our state-of-the-art telescopes and an expert guide to answer all of your questions and to show you everything you'd want to see. It's the perfect nighttime activity to add to your Lake Arrowhead trip.
A comparison of the night sky under different Bortle levels. The difference is clear. Image Credit: ESO/P. Horálek, M. Wallner (CC-BY 4.0)