McDonald Observatory – The Darkest Night Skies in the Lower 48 (by Chris)…

As our travels continue through the west side of Texas, this often forgotten area continues to reveal its secrets to us.  Fort Davis is located a couple of hours North of Big Bend National Park, and is home to the McDonald Observatory.  We have always been enchanted by the night sky, especially on clear nights when we find ourselves far away from civilization.  The best night sky we have seen on our trip prior to Fort Davis was our first night in the Badlands in South Dakota.  We could clearly see the Milky Way Galaxy and layers upon layers of stars.  Naturally, we were excited to explore McDonald Observatory to not only enjoy the night sky, but also get a chance to look through some of the largest telescopes we have ever seen to get a glimpse into the depths of our solar system.

McDonald Observatory - How to enjoy the darkest night skies in the lower 48!

The McDonald Observatory is known globally in the astronomy world.  It was constructed in the late 1930’s after a Texas banker, William Johnson McDonald, left the bulk of his fortune to the University of Texas at Austin with the purpose of constructing a top notch Astronomical Observatory.  The Davis Mountain location was ideal because it happens to offer some of the darkest skies in the country.  The map below has a circle around Big Bend NP, the observatory is just to the Northwest of it.

Dark sky map

The observatories main telescopes are spread over two mountains – Mt. Locke and Mt. Fowlkes.  The view atop Mt. Fowlkes is breathtaking during the day and gives you an appreciation for how isolated this location is.

View from atop Mt. Fowlkes

The beauty of the area can be seen at great distances and also up close with a nearby flowering cactus…

flowering cactus

The observatory is home to a number of impressive telescopes, with three in particular getting a lot of the attention:



The telescope on the left was the first large telescope constructed on the grounds and is known as the Otto Struve Telescope.  It has an 82-inch mirror and was the second largest telescope in the world at the time of its completion.  To over simplify it, telescopes are really all about gathering light.  The more light you can gather, the farther you can see and the more clear the image.  The mirrors are used for gathering this light.  The telescope on the right is known as the Harlen J. Smith Telescope, completed in 1968, and has a 107-inch mirror which was the third largest telescope in the world at the time of its completion.  Both of these telescopes are still in use today.  Astronomers from all over the world schedule time to visit the observatory and use the telescopes for experiments and viewing deep into space.Hobby Eberly Telescope

The third telescope is known as the Hobby-Eberly Telescope (HET) and is not your typical telescope.  Constructed in such a way that it can still perform the majority of normal functions of a telescope, the cost of the telescope was roughly 20% of what an optical telescope of a similar size would have been.  It doesn’t have the full mobility of a typical large telescope but can still view 81% of the sky, leaving out the portions nearest the horizon which are typically avoided by telescopes anyway.  The design concept was developed by two gentlemen in the astronomy program at Penn State University (Go Lions!!).

Hobby Eberly Telescope interior


Its tough to make much out in the picture, it was taken inside the HET.  What it does give you an idea of is the scale of this beast.  The blue truss members in the lower third of the picture are what supports the mirror panels.  The overall mirror is actually made up of 91 individual segments all pieced together.  Each segment weighs 250 lbs!

The observatory also offers “star parties” every Tuesday, Friday and Saturday.  We happened to be in the area over a Tuesday night and were blessed with a moonless, cloudless night – ideal for star gazing!  These parties are very popular and they recommend making online reservations but we also read that they do not sell-out, and that the fee is nonrefundable – so weight that information before you make a reservation.  We had a “small” group the night we went and there were still over 200 people there!star party

Given the time of the year, our program started at 9:30 pm and went for two hours.  The party starts off with a 30 minute presentation by one of the observatory astronomers and gives you an in depth tour of the constellations overhead, along with any planets that may be visible at the time.  The rest of the time is spent viewing through the different telescopes (and waiting in line at each one).  They had seven telescopes set up, the largest of which was 24″ in diameter.  They don’t let you get into the larger telescopes featured above, those are reserved for the professionals!  Two of the largest telescopes that we were able to look through were both trained on Jupiter, and we were able to clearly make out the dark stripes typical of Jupiter as well as four of Jupiter’s moons.  The other telescopes were focused on various star clusters.  Honestly, I think we enjoyed waiting in line at each telescope as much as we did looking through the telescopes.  Taking in the night sky in all its brilliance was wonderful, and something we won’t soon forget.  It is impressive to think that all of those stars are up there every night, but most times we just can’t see them because of all the light we are typically surrounded with.  The best way I could describe it is like having a blanket of stars draped over the earth, even though you know you are looking out into infinite space the curvature of the Earth never felt more apparent to me.  It was a wonderfully humbling reminder of just how beautiful and expansive Creation is, and just how small we are.


  • For visiting the McDonald Observatory, the most convenient accommodations are located in Fort Davis which lies 15 miles to the southeast.
  • Self guided tours are available and are FREE!  You can go up on Mount Fowlkes and Mount Locke and to get up close to the telescope enclosures.  There is a viewing window that allows you to see the “guts” of the Hobby-Eberly Telescope.  The other two large telescopes can only be seen in detail via guided tours that require a fee.
  • Star parties are very popular, if you plan to attend one of these make sure you pick one of the nights that they are offered.  The fee was $12.00 per adult.
  • There are rules as to where you can drive after night fall to make sure that your headlights do not interfere with the work of the astronomers.  They will explain at the visitor center and during the star party.


About Jen

I love travel, which led me to become a fulltime RVer. I love wellness, which I can talk about 'til the cows come home. I love being self-employed, which means I get to dabble in what interests me from essential oils to RV planners. But most importantly, I love my husband and our life together on the road!

1 comment on “McDonald Observatory – The Darkest Night Skies in the Lower 48 (by Chris)…

  1. I Would love to see the stars! That flowering cactus is really beautiful too!

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