MICHIGAN BASIN CORE RESEARCH LABORATORY - This collection, housed at Western Michigan University, contains 375 wells and nearly 60,000 feet of core. The index is sorted by county and lists operator, Well name, Permit number and footage cored. - More information about this repository

MARATHON OIL COMPANY - Marathon Oil Company's Collection of Michigan Well cores. Currently housed at Western Michigan University.

***NEW***UNIVERSITY OF MICHIGAN CORE COLLECTION - Currently housed by the Department of Geological Sciences at the University of Michigan, Ann Arbor. This collection contains over 540 wells and is in excess of 90,000 feet of core.

***UPDATED***WAYNE STATE UNIVERSITY - Wayne State University collection contains 74 wells and about 12,000 feet of core predominately from Southeastern and Central Michigan

TEXAS BUREAU OF ECONOMIC GEOLOGY - Large collection of over 140 wells in the collection of the Texas Bureau of Economic Geology. Most wells were drilled by Shell or Sun Oil Companies. Contact the Texas BEG for more information regarding these cores.

STATE OF MICHIGAN OIL AND GAS WELL CORES - Collection of 42 Michigan Oil and Gas Well Cores, about 5000 feet of core, housed in Marquette - (More information about this repository) . Also stored at this facility are mining cores form the Upper Peninsula and Miscellaneous mineral well cores, environmental well cores, outcrop samples and drill cuttings from mineral and oil and gas wells. Catalogue of the Complete collection in Marquette

U.S.GEOLOGICAL SURVEY MICHIGAN CORES - Small collection of Michigan cores stored at the U.S.G.S. repository in Denver. This repository has a large national collection indexed by state.

UNOCAL MICHIGAN CORES Unocal's Michigan core collection housed at C&M Facility in Schulenberg, Texas. There are 14 cored wells in this collection.

Central Michigan University Geology Department - Contact Kathy Bennison - collection consists of about 15 cored wells, about 1000 feet of core, and a large catalogued collection of drill cuttings.