This report is part of a seven-volume series on the Hanna, Wyoming, underground coal gasification field tests. Volume 1 is a summary of the project and each of Volumes 2 through 6 describes a particular test. Volume 7 is a compilation of all the data for the tests in Volumes 2 through 6. The reports in this series include: The Hanna IV test was designed as the first underground coal gasification test using commercial well spacings of 100 and 150 feet between well pairs in a linear 3-well pattern. The test was initiated in late 1977 and completed in late 1979. This long duration was due to unfavorable geologic conditions (faulting) which could not be successfully overcome resulting in the test being split into Hanna IVA and Hanna IVB with about one year between the conduct of each. This report covers: (1) specific site selection and characteristics; (2) test objectives; (3) facility description; (4) pre-operation tests; (5) test operations summary; and (6) post-test activity. 5 refs., 19 figs., 13 tabs.