Getting Out of Town, but to Where?

This post is going to be an exercise in overthinking a simple task like combining imaging and camping, much like the many posts I've made about batteries and such. Wander in at your own risk. 

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Last time I said this post would be about some parks I visited in the hope of finding a nice dark place at which to image and camp. Here are the results of that little jaunt and the realization it forced upon me. 

• Cedar Hanson County Park near Trimont: Very nice for campers, but too many trees
• Sands Country Cove campground southwest of St. James: High density, packed even in April, which is not the nicest month to tour Minnesota. Reservations will be tight, just like how it packs the RVs together. It looks like it caters to families with big RVs. On the other hand, no trees.
• Eagle's Nest County Park east of St. James: Needs a variance to park away from trees in an open pasture that's probably dedicated to horse riders. I've written to the county parks person about that variance, but this is a "light green" light pollution area so not much darker than a local site.
• Voss Park, Butterfield: A large area of trees was removed and sites added since my last visit. It's also not much darker than a non-camping site I use now.
• Lake Hanska County Park, north of La Salle: Too many trees.

Yes, that's correct, none of these were suitable.

Related: An article by the Dyrt.com reports on a poll of 7000 campers. One result was

"In 2023, 45.5% of campers reported difficulty booking a site because a campground was sold out. It was four-times harder to find an available campsite to book than it was in 2019, when just 10.6% of campers reported difficulty."

Here is the realization: Campground reservations are a necessity. Sure, some campgrounds say they are first-come, first-serve. Theoretically you can see a good forecast in the morning, hop in the car and drive three hours to one of those campgrounds hoping there's an available spot for the night. But the chances are that spot will be gone by the time you get there, meaning you have to turn around and drive three hours back home. Not good. Minnesota state parks do allow same-day reservations, but your chance of that working in your favor seems particularly small if you want more than one consecutive night.

 

The problem with advance reservations is the same as that with multi-day star parties: the weather. You can't know what you're going to get.  But unlike star parties with registration fees and associated travel expenses, camping reservations do give you an out. You can cancel the reservation and get some (or most) of your money back, and then complain about the clouds from the comfort of your own home.

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The Hunt for Darkness

Let's say you enjoy camping and want to combine that with dark-sky imaging as an alternative to attending distant star parties.

Choosing when to camp is easy, just mesh your personal schedule with any time the moon isn't a bother. Then match that to campground availability. 

Deciding Where to camp is a little tougher. If you live in a light-polluted city you'll probably need to drive one to three hours to find dark sky.  That means you should think about what your daily safe driving range is. That's the amount of time you can stay alert and your back won't punish you the next day. For me, old and decrepit as I am, that range is about six hours. For the rest of this post I'll assume a driving range of half that -- three hours -- because that permits turning around and returning home if a crucial item was forgotten ("OMG I forgot the counterweight!"). 

With your driving range decided you can start your hunt for campsites that are reasonably dark, accept reservations, and have open sky. And I do mean hunt because campgrounds satisfying all three conditions seem to be rather rare. Some camp sites may be dark enough overhead but have troublesome horizon light domes from nearby cities in the direction you want to image. Many camps are full of shade trees that block the sky. Some like to maximize land usage by packing large RVs so tightly together that they obstruct the sky. Some are near major highways and almost impossible to book. Some are rather primitive. Will you need power and water? Flush toilets? A shower? Everyone has a particular set of requirements.  If you need to run a generator after 10 P.M. you may have issues with a campground's quiet time. And some smaller parks are just sort of unkempt or creepy, making you wonder if they're a "party park" for locals (see for example, Pine Ridge Park north of Herman). Your hunt is for a camp where you can securely image and enjoy yourself while doing so.

It's almost May now and places are taking reservations: it's time to get site hunting. For this post I used Google search, Google Earth, Google Maps, and Light Pollution Atlas 2006 (selecting the 2022 overlay). Google Earth showed me if the locations are infested with trees, Google Maps provided directions and drive times, and the Light Pollution Atlas was great for figuring out how dark a site is and what the horizon situation might be.

Other online resources that were helpful included Minnesota's state park finder and a map of Minnesota's counties. Googling a county name will point you to the county's home page, and from there you can see what it has for parks. A few counties structure their web sites as if they don't want anyone to know they have parks, so be ready to dig.

There are a lot of campground finders on the internet, two that seemed useful are Hipcamp for smaller private camps and The Dyrt for pretty much everything else.

My personal site hunt was limited to the south and west of the Twin Cities because I enjoy that part of the state and it's less tree-infested than elsewhere. You're free to hunt wherever you want. But first we should think about just how dark we want it to be.

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What is Dark Enough, and What is Too Dark?

I know, I know, there's no such thing as "too dark."  But there can be a dark so dark that it can't be reached within your driving time limit.

My very subjective take on "dark enough" is based mainly on my past imaging at different sites. 

First a bit of terminology: the Light Pollution Ratio, or LPR. LPR is the ratio of light pollution to natural sky brightness; an LPR of 1.0 means that the light pollution is equal to the natural sky brightness. The smaller the LPR the darker the sky. (The Light Pollution Atlas gives you the LPR when you click on its map.)

The diagram below shows an LPR diagram from the Light Pollution Atlas 2022 overlay. The area covered is from near the South Dakota border at left to a bit past Eau Claire WI at right, and just south of Duluth at top to Albert Lea at bottom. Color indicates LPR value with light green being between 0.6 and 1.0; dark green is 0.33 to 0.6. I've changed all areas with LPR greater than 3 to black.

Light pollution map of southern Minnesota. Click to enlarge! 

My back yard has an LPR of 24.5 (!), which is emphatically awful. If I want to image emission nebulae it's narrowband filter time. LRGB imaging (my preference) works well from Eagle Lake (LPR 2.34, EL on the diagram) and Starhome (a friend's back yard, LPR 2.9, SH on the diagram). They're both on the fringe of the Metro and suffer from its huge light dome. Cherry Grove (LPR 1.08, CG on the diagram) is located south of the cities and is very good overhead but less so northward and to the southeast. A person I corresponded with during my Astronomical League Bright Nebula imaging years was using LRGB from a Missouri site with an LPR of 0.6 and his images were nothing less than excellent. I've also imaged from locations where the LPR is under 0.2 and can attest to their excellence.

My take is that an LPR > 7 or so will push you to use narrowband or at least multiband filters. An LPR < 7 is probably dark enough for LRGB imaging of most targets, and an LPR < 0.6 is great for almost any DSO. If you're planning to go super deep, like imaging IFN, then you probably want it as dark as possible to reduce your total exposure time.

My hunting goal will be to find locations where the LPR is 0.6 or less; my motto will be "Go Dark Green or Stay Home." You may be willing to accept something brighter, or demand even darker based on your imaging gear and targets.

Once I determined my personal "dark enough" I could perform my hunt. What follows is the result. See the summary at the end of this post for campground LPR values, links to the individual parks/campgrounds, and other comments.

Minnesota State Parks

Minnesota state parks are widely regarded as some of the nicest in the country. The facilities are well maintained and staffed by knowledgeable outdoor enthusiasts. And lucky for us there are two parks that may be particularly suitable for imagers!

Not suitable -- either too bright or blocked sky: Big Stone Lake, Blue Mounds, Camden, Flandrau, Fort Ridgely, Glacial Lakes, Kilen Woods (probably), Lake Maria, Minneopa, Minnesota Valley, Monson Lake, Myre Big Island, Sakatah Lake, Sibley, Split Rock Creek

 

Suitable: Lac qui Parle and Lake Shetek.

Lac qui Parle is a little darker than Lake Shetek but Montevideo to the southeast maye put up a light dome. One person who has been there said he did not note any problem with the horizon. The positions of these parks are indicated on the diagram above. Both parks can be found in its lower left corner.

All state parks require reservations.

Minnesota County Parks

County parks operate on generally lower budgets and their facilities vary widely. Even so, they will likely be packed full of campers during summer. An additional factor for these parks are monthly and seasonal campers who will fill spaces semi-permanently. A brief look at County parks shows a few promising locations:

Jackson County: Sandy Point (reservation required, choose site carefully to avoid trees, needs a visit to verify horizons)  

Murray County: Sundquist, Lime, and Swenson (no reservations)

Lincoln County: Picnic Point  and Norwegian Creek (reservations required)

Lyon County: Twin Lakes (reservations required)

Yellow Medicine County: Timm Park. Needs a visit to see which if any sites are suitable. (reservations required)

Counties that have no suitable county parks are Blue Earth, Brown, Chippewa, Cottonwood, Faribault, Freeborn, Kandiyohi, Martin, McLeod, Meeker, Mower, Nicollet, Nobles, Pipestone, Redwood, Renville, Rock, Sibley, Swift, Watonwan 

Minnesota City and Town Parks

Many small cities and towns have parks that offer camping. These are generally near the population center and so will have considerable light pollution. I found none that were satisfactory for imaging. 

Private Campgrounds

I am omitting campgrounds that pack RVs tight together; giant RVs are as opaque as trees. 

All of the following locations need to be visited to assess their suitability.

Camping on Private Lake. This was found on Hipcamp. It has an LPR of only 0.3! You would need to talk to the owner about being able to set up away from the trees. If you don't need AC power siting might be easier. Reservations required.

Camp Summit in Hadley. Seven sites, accepts reservations, but also allows space-available. LPR = 0.45

Talking Waters in Gary, SD. Many sites, requires reservations. LPR = 0.51

Niemackl Lake near Herman, MN. Accepts reservations by phone. LPR = 0.26. I visited this a few years ago and found maybe 3 or four of the 10 sites were decent. Neimackl has the distinction of being the darkest campground in my survey!

There are a few places in northern Iowa that look very good, but they are generally about 3 hours distant and will be very busy.

There are probably other suitable private campgrounds. If you know of some please let me know.

Summary: The Too-Short List of Suitable Campgrounds In SW Minnesota

This omits campgrounds that need a visit to judge suitability. (Trees look bigger in person than on Google Earth!) 

Reservations required:

Lake Shetek S.P., LPR = 0.52, use only the Sunrise Campground

Lac qui Parle S.P., LPR = 0.37, use only the Upper Campground

Twin Lakes C.P., LPR = 0.43, only north portion can be reserved at this time

Picnic Point C.P., LPR = 0.42

Norwegian Creek C.P., LPR  = 0.51

Reservations not accepted:

Sundquist C.P. , LPR = 0.35

Lime C.P., LPR = 0.43

Swenson C.P., LPR = 0.41

If you have experience imaging at these or others, let me know how you liked the location!