Photo by John Mahony       

Photo by John Mahony

A group of Girl Scouts inspects the 16" LX200R, with the dome for the 7" refractor in the background.

Prairie Grass Observatory is located under dark rural skies at Camp Cullom (Clinton County Foundation for Youth), between Mulberry and Frankfort, Indiana, and is available to the public.  Technical assistance is provided by the Wabash Valley Astronomical Society in Lafayette.

The observatory has four telescopes:  a huge 28" aperture Dobsonian, a 16" LX200R Schmidt-Cassegrain telescope, a 16" Newtonian telescope, and a 7" apochromatic refractor.  The observatory also has a pair of giant 25/40X100 binoculars, and a hydrogen-alpha filter for solar viewing. Click here for more info on these scopes and other equipment at the observatory.

Indiana Family Star Party 2015

Will be held July 15-19, 2015 at Camp Cullom.

Pictures from last year are here.

Public Viewing Events

  International Space Station
Photo by John Mahony

The International Space Station and other satellites can be viewed through the observatory's 16" LX200R telescope.

Click here for a schedule of upcoming public viewing events.
In order to avoid bright headlights in the observing area, please use the parking lot east of the Nature center.

The observatory is also available at special request for group viewing events.  Contact Russ Kaspar at or John Mahony at

Need directions to the site? Here's a map (includes a map of Camp Cullom).

Parking is east of the Nature Center.


This image of Jupiter was taken by John Mahony during a night of exceptionally stable air during the 2010 Indiana Family Star Party,
 using a Toucam webcam in our 16" LX200R.  The object at upper left is one of Jupiter's moons.

Doug Sanqunetti took this image of the Whirlpool Galaxy (M51) using his own
telescope on the PGO grounds.  Doug is one of several local area amateur astronomers
who bring their own telescopes to use under the dark rural skies of Camp Cullom.

Click here for more astrophotography of the sun and moon, the planets, star clusters, nebulae, and galaxies.
All images taken at PGO

H-alpha Solar View

Here's a photo of a solar prominence taken through our H-alpha solar filter.
Click on the photo for more.

Prairie Grass Observatory is an official asteroid tracking/discovery station.
20 asteroids have been discovered at PGO, and numerous
 follow-up observations of newly discovered near-earth asteroids have been made.

Click to subscribe to pg_obs
The observatory has two "Yahoo Groups" e-mail lists.  Both are open to the public.  The first, on the left, is the "official" observatory mail list and is used primarily only for notices of public events at the observatory.  The second, on the right, will also include notices of events at nearby astronomy clubs, and can also be used for general discussions of astronomy and telescope equipment, and can be used by local amateur astronomers in the area to arrange observing get-togethers at Camp Cullom or elsewhere.

Click to subscribe to pg-astro

Clear Sky Chart

There is power (both a.c. and 12v d.c.) available at the site, and water and restrooms at the camp's Nature Center, about 75 yards away.  There are two concrete observing pads and a picnic table located at the west end of the observatory area, so you can bring your own telescope there even on nights when the observatory is not open.  But be sure to call the camp ranger ahead of time (see below for phone#), since the camp is occasionally closed for special events.

The observatory is named "Prairie Grass Observatory" because it is located in the middle of one of the largest stands of native prairie grass in the state.

Click here for a history of the development of Prairie Grass Observatory.
For those considering building a small observatory, construction details are available here.

Click here to see Clinton County's light pollution ordinance.

The observatory is part of Camp Cullom, which is operated by the Clinton County Foundation for Youth.
For more information on the observatory itself, contact Russ Kaspar at or John Mahony at

Camp Cullom phone: (765)296-2753  Note that this is the camp ranger's home phone, do not call after 10 pm!
This is a local call from both Lafayette and Frankfort.

MPC H59          Latitude:  N4018'48"       Longitude:  W8638'05"       Elevation:  249m (817 ft.)