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.

The Indiana Family Star Party for 2020 has been cancelled due to the COVID-19 pandemic.  At this time we are offering “Space Nights at Camp Cullom”, a free, limited-participation event consisting of camping and observing with your own telescope.  This is a social distancing observing event.  Click here for more information about this event.

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.

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.)

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.


The observatory has a Groups.IO e-mail list that is open to the public.  The list is the "official" observatory mail list and is used for notices of public events at the observatory 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.
Clear Sky Chart

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 to see Clinton County's light pollution ordinance.

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.)

Latitude:  N40º18'48"       Longitude:  W86º38'05"       Elevation:  249m (817 ft.)

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