Petrology, geochemistry and paleomagnetism have been collectively used to examine the process and timing of both dolomitization and hydrocarbon migration in carbonates from the Mississippian Mount Head Formation of the Shell Waterton gas field in the foothills of the Rocky Mountains of southwestern Alberta, Plugs were sampled from three unoriented drill cores and their azimuths were measured with respect to a master orientation line (MOL) on fitted segments of each core to provide the relative orientation between specimens from different plugs. The MOL azimuth was obtained by: 1) comparison of features observed in the core with those observed in the oriented Formation Micro-Scanner (FMS) logs; and, 2) aligning the low temperature magnetization direction with the present Earth＇s magnetic field (PEMF). Both methods gave similar results, showing that paleomagnetism can be an effective and inexpensive alternative for orienting drill core for which FMS logs are not available. Thermal demagnetization proved to be vastly superior to alternating field demagnetization at separating the PEMF direction from the ancient magnetizations. Dolomite and anhydrite from Well 44 yielded PEMF directions between 150 degrees and 300 degrees C (10 to 50 mT) and syndepositional Paleozoic directions above 300 degrees C after correction for a minor clockwise vertical axis rotation on the thrust sheet. Geochemical analyses yielded Sr-86/Sr-87, delta(13)C and delta(18)O values that are consistent with postulated Mississippian seawater values and the petrography indicates little or no diagenetic alteration. Dolomite from Wells 50 and 53 yielded PEMF directions also in the 150 degrees to 300 degrees C (10 to 50 mT) range, but reversed Cretaceous magnetizations above 300 degrees C with the latter being much more pronounced in Well 53. These dolomites also showed much more isotopic and petrographic variation than in Well 44, indicating significant diagenetic alteration. The paleomagnetic results suggest that most of this alteration occurred during basinal fluid flow associated with Laramide deformation during the Late Cretaceous to Paleocene, It is possible that these data are recording the migration of gas into the Waterton trap. If this proves true, then the combined use of paleomagnetism, geochemistry and petrography may prove to be a useful tool to date and identify pathways for the migration of hydrocarbons.