LIVE REPORT! Munich Show 2026 - last updated 0 minutes ago. Click here to watch.
Log InRegister
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreOur ScienceMindat Newsletter [Free Download]Contact Us
Donate to MindatSponsor a PageCorporate SponsorshipSponsored Pages
Learning CenterWhat Is a Mineral?The Most Common Minerals on EarthInformation for EducatorsMindat ArticlesMindat Newsletter [Free Download]The ElementsThe Mineral Quiz
Search FormMinerals by PropertiesMinerals by ChemistryMineral Visual ExplorerAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDMinerals by CountryAlphabetical Mineral IndexAlphabetical Locality SearchMineral Association SearchList of CountriesLocalities Near MePhoto SearchSearch ArticlesSearch GlossaryThe Rock H. Currier Digital LibraryMore Search Options
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
MineralsPetrologyFossilsMeteoritesGeologic Time
Mining CompaniesStatisticsMineral MuseumsClubs & OrganizationsMineral Shows & EventsDevice SettingsTime Machine
Read DiscussionsIdentification Request
Photo SearchPhoto GalleriesSearch by ColourPhoto Colour ExplorerNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

Lake Monroe, Monroe County, Indiana, USAi
Regional Level Types
Lake MonroeLake
Monroe CountyCounty
IndianaState
USACountry

This page is currently not sponsored. Click here to sponsor this page.
PhotosMapsSearchMineralogy
Latitude & Longitude (WGS84):
39° 0' 25'' North , 86° 30' 10'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
PlacePopulationDistance
Harrodsburg691 (2017)3.7km
Smithville-Sanders3,184 (2017)5.9km
Avoca583 (2017)11.3km
Oolitic1,156 (2017)12.0km
Bedford13,347 (2017)16.3km
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
ClubLocationDistance
Lawrence County Rock Club, IncBedford, Indiana16km
Brown County Rock and Mineral ClubNashville, Indiana31km
Mindat Locality ID:
30741
Long-form identifier:
mindat:1:2:30741:0
GUID (UUID V4):
0
Other/historical names associated with this locality:
Monroe Lake; Monroe Reservoir


Permission from the U. S. Army Corps of Engineers ranger is required.
MONROE RESERVOIR (LAKE), 39.058483, -86.454761

Monroe Lake (also an Indiana State Park, see http://www.in.gov/dnr/parklake/2954.htm was constructed in 1964 by the Army Core of Engineers as flood control and the water supply for Bloomington, Indiana and surrounding smaller communities. Excluding Lake Michigan, it is the largest lake in the state, 10,500 acres. According to local expert and collector Bob Harman: “a wooded ridge about 40' to 60' high runs parallel to part of the South shore of the lake. Midway along this ridge, the spillway was blasted out of the Indiana limestone. It is now a wide flat area, now used for parking and a picnic area with access down to the lakeshore. The blasted walls, up to 60' high, are on both the East and West sides of this flat area. About 40' up on both East and West spillway sides, or about 10' - 15' below the forest floor there is a 5' - 6' geodized zone of limestone that has been worked for years. There are little alcoves in the rock in this zone with many high quality geodes found in the 50+ years since discovery. It is not for the faint of heart as getting there by climbing through the woods to the spillway wall edge is difficult and one small misstep in the collecting alcoves means you fall down the spillway wall. In the woods along this ridge are found large weathered out geodes with great barites, but most are not as fresh as those collected directly from the spillway rock.”

There are several general localities around the reservoir which could be better described by local collectors. The spillway location is known for barite, calcite, quartz and dolomite, although dolomite is now quite as common at the spillway as at other locations, or at the State Route 37 road cuts State Route 37 roadcut (Indiana Geological Society Bulletin 18 location 20), Harrodsburg, Monroe County, Indiana, USA. Also according to Harman, “…the road leading to this spillway area goes past the dam on the lake. As such it is known as Dam Road. It goes up a short hill with a small road cut just outside the spillway area. This locality is known as “barite hill” as collecting here over the years has yielded many barite-containing geodes. The short road cut here is severely undercut from extensive collecting and the overhang is now falling in, essentially bringing collecting to a halt. Round the back side of this road cut and further up the road it becomes Mission Valley Road. There are wooded areas which are quite hilly and descend into ravine areas called the “Mission Vally location,” about 0.5 - 1.0 miles from the spillway.”

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


6 valid minerals.

Rock Types Recorded


Select Rock List Type

Alphabetical List Tree Diagram

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
ⓘPyrite2.EB.05aFeS2
Group 4 - Oxides and Hydroxides
ⓘQuartz4.DA.05SiO2
Group 5 - Nitrates and Carbonates
ⓘCalcite5.AB.05CaCO3
ⓘDolomite5.AB.10CaMg(CO3)2
ⓘAragonite5.AB.15CaCO3
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
ⓘBaryte7.AD.35BaSO4

List of minerals for each chemical element

CCarbon
Cⓘ AragoniteCaCO3
Cⓘ CalciteCaCO3
Cⓘ DolomiteCaMg(CO3)2
OOxygen
Oⓘ AragoniteCaCO3
Oⓘ BaryteBaSO4
Oⓘ CalciteCaCO3
Oⓘ DolomiteCaMg(CO3)2
Oⓘ QuartzSiO2
MgMagnesium
Mgⓘ DolomiteCaMg(CO3)2
SiSilicon
Siⓘ QuartzSiO2
SSulfur
Sⓘ BaryteBaSO4
Sⓘ PyriteFeS2
CaCalcium
Caⓘ AragoniteCaCO3
Caⓘ CalciteCaCO3
Caⓘ DolomiteCaMg(CO3)2
FeIron
Feⓘ PyriteFeS2
BaBarium
Baⓘ BaryteBaSO4

Other Regions, Features and Areas containing this locality


This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

 
and/or  
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph and Ida Chau.
Content on this site may not be used to train, fine-tune, or otherwise develop artificial intelligence or machine learning models without prior written permission - see our Terms & Conditions.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: October 22, 2026 07:32:23 Page updated: July 24, 2026 09:18:17
Go to top of page