• Geologic mapping of the Canby and portions of the Oregon City and Gladstone 7.5 minute quadrangles (with Marv Beeson).


• Preparing final drafts of the geologic maps and cross-sections of the Salem West, Sidney, and Stayton 7.5 minute quadrangles (with Marv Beeson and Karen Wheeler).


• Serve as lead hydrogeologist on an on-going project to develop a 1:100,000 scale, 3-D model of the suprabasalt sediment and Columbia River basalt units that host aquifers that underlies Grant, Franklin, and Adams Counties in the central Columbia Plateau, Washington. This hydrostratigraphic framework project is being done under contract to the Columbia Basin Groundwater Management Area by Kennedy/Jenks Consultants.

Tolan, T.L., and Beeson, M.H., in preparation, Geologic map and digital database of the Canby and portions of the Oregon City and Gladstone 7.5 minute quadrangles, Oregon: U.S. Geological Survey Open-File Report.

Beeson, M.H., and Tolan, T.L., in preparation, Geologic map and digital database of the Salem West 7.5 minute quadrangles, Oregon: U.S. Geological Survey Open-File Report.

Tolan, T.L., and Beeson, M.H., in preparation, Geologic map of the Sidney 7.5 minute quadrangles, Oregon: U.S. Geological Survey Open-File Report.

Tolan, T.L., and Beeson, M.H., in preparation, Geologic map and digital database of the Stayton 7.5 minute quadrangle, Oregon: U.S. Geological Survey Open-File Report.

Anderson, J.L. and Tolan, T.L., in press, Geologic map of the Satus Pass 15 minute, and northern part of the Quinton and Rufus 7.5 minute quadrangles, Washington: State of Washington, Department of Natural Resources map, GM series.

Tolan, T.L., and Beeson, M.H., 2002, Some geologic factors that influence groundwater availability in the Columbia River Basalt Group (CRBG) aquifer system in the Willamette Valley, Oregon: Geological Society of America Abstracts with Programs, v. 34, no. 5.

Beeson, M.H., and Tolan, T.L., 2002, Basalt of Huntzinger, Asotin Member of the Saddle Mountains Basalt, Columbia River Basalt Group (CRBG) identified in western Washington: Geological Society of America Abstracts with Programs, v. 34, no. 5.

Lindsey, K.A., and Tolan, T.L., 2001, Hydrogeologic setting of the Columbia Basin Groundwater Management Area - a summary report, in, Kennedy/Jenks Consultants, Hydrogeologic Characterization Report, Columbia Basin Ground Water Management Area: Franklin County Conservation District, Pasco, Washington, Appendix A, 71 p.

Tolan, T.L., Beeson, M.H., and DuRoss, C.B., 2000, Geologic map and database of the Salem East and Turner 7.5 minute quadrangles, Marion County, Oregon - a digital database: U.S. Geological Survey Open-File Report 00-351, scale 1:24,000, http://geopubs.wr.usgs.gov/open-file/of00-351.

Blakely, R.J., Wells, R.E., Tolan, T.L., Beeson, M.H., Trehu, A.M., and Liberty, L.M., 2000, New aeromagnetic data reveals large strike-slip faults in the northern Willamette Valley, Oregon: Geological Society of America Bulletin, v. 112, no. 7, p. 1225-1233.

Tolan, T.L., Campbell, N.P., and Lindsey, K.A., 2000, Exploring the hydrogeology of the Columbia River Basalt Group - a field guide to selected localities in the Columbia Plateau, Washington: Third Washington State Hydrogeology Symposium, October 14-15, 2000, Tacoma, Washington, 66 p.

Tolan, T.L., and Lindsey, K.A., 2000, Hydrogeologic evaluation of the Port of Morrow well number 4, Umatilla Basin, Oregon: Daniel B. Stephens & Associates, Inc., Richland, Washington, consultant report prepared for the Port of Morrow, Boardman, Oregon, v. 1 & 2, 98 p., 2 plates.

Tolan, T.L., Reidel, S.P., Johnson, V., Lindsey, K.A., and Beeson, M.H., 2000, Columbia River Basalt Group (CRBG) and groundwater - understanding the physical framework of flood-basalt aquifer systems: Geological Society of America Abstracts with Programs, v. 32, no. 8,p. A72.

Tolan, T.L., Beeson, M.H., and Wheeler, K.L., 1999, Geologic Map of the Scotts Mills, Silverton, and Stayton Northeast 7.5 Minute Quadrangles, Northwest Oregon: A Digital Database, U.S. Geological Survey Open-File Report 99-141, 40 p., 2 sheets, scale 1:24,000, http://wrgis.wr.usgs.gov/open-file/of99-141.

Percy, D.C., Beeson, M.H., James, D.H., Haug, B.J., Nouzillier, F., Cowburn, S., Tolan, T.L., and Burns, S.F., 1998, Geochemical stratigraphy of Missoula flood rhythmites: Geological Society of America Abstracts with Programs, v. 30, no. 5, p. 59.

Lindsey, K.A., and Tolan, T.L., 1997, Stratigraphy and sedimentology of late Neogene suprabasalt sedimentary units in the Yakima Fold Belt - some geologic constraints on ground water flow in suprabasalt aquifers in the Mid-Columbia region or debunking misconceptions about sediments overlying the Columbia River Basalt Group, in, Washington Hydrological Society, Proceedings from the 2nd symposium on the hydrology of Washington State: Washington Department of Ecology, Olympia, Washington, p. 20.

Beeson, M.H. and Tolan, T.L., 1997, Geologic "news" from the Westside Tunnel: Association of Engineering Geologist Program with Abstracts, 40th Annual Meeting, Portland, Oregon, p. 84.

Conrey, R.M., Uto, K., Uchiumi, S., Beeson, M.H., Madin, I.P., Tolan, T.L., and Swanson, D.A., 1996, Potassium-argon ages of Boring Lava, northwest Oregon and southwest Washington: Isochron/West, no. 63, p. 3-9.

Beeson, M.H., and Tolan, T.L., 1996, Field trip guide to Columbia River Basalt intracanyon flows in western Oregon and Washington - Ginkgo, Rosalia, and Pomona flows: Cordilleran section meeting of the Geological Society of America, Portland, Oregon, 35 p.

Tolan, T.L., Lindsey, K.A., and Beeson, M.H., 1996, Neogene paleodrainage implications of exotic clast lithologies in the Chenoweth (Dalles) Formation, Oregon - rediscovery of old truths about the Dalles Formation: Geological Society of America Abstracts with Programs, v. 28, no. 5, p. 118.

Lindsey, K.A., and Tolan, T.L., 1996, Rediscovery of Late Neogene lacustrine deposits in the western Umatilla Basin - implications for basin evolution and paleodrainage history, north-central Oregon and south-central Washington: Geological Society of America Abstracts with Programs, v. 28, no. 5, p. 85.

Reidel, S.P., Beeson, M.H., Tolan, T.L., and Lindsey, K.A., 1996, The age of La Grande Basin (LGB), northeast Oregon - new evidence for middle Miocene deformation and basin formation: Geological Society of America Abstracts with Programs, v. 28, no. 5, p. 104.

Reidel, S.P., Tolan, T.L., and Beeson, M.H. 1994. Factors that influenced the eruptive and emplacement histories of flood basalt flows - a field guide to selected vents and flows of the Columbia River Basalt Group, in, Swanson, D.A., and Haugerud, R.A., eds., Geologic Field Trips in the Pacific Northwest, Geological Society of America Annual Meeting, Seattle, Washington, chapter 1B, p. 1B.1 - 1B.20.

Reidel, S.P., and Tolan, T.L., 1994, Late Cenozoic structure and correlation to seismicity along the Olympic-Wallowa Lineament, northwest United States (Discussion and Reply) - Discussion: Geological Society of America Bulletin v. 106, no. 12, p. 1634-1638.

Lindsey, K.A., Tolan, T.L., and Reidel, S.P., 1993, New insights into the origin of the Late Neogene sediments in the Umatilla Basin, north-central Oregon and south-central Washington: Geological Society of America Abstracts with Programs, v. 25, no. 5, p. 70.

Reidel, S.P., and Tolan, T.L., 1992, Eruption and emplacement of flood basalt - an example from the large-volume Teepee Butte Member, Columbia River Basalt Group: Geological Society of America Bulletin, v. 104, no. 12, p. 1650-1671.

Beeson, M.H., Tolan, T.L., and Madin, I., 1991, Geologic map of the Portland quadrangle, Oregon: State of Oregon Department of Geology and Mineral Industries map, GMS 75, scale 1:24,000.

Tolan, T.L., Reidel, S.P., and Fecht, K.R., 1991, The unusual occurrence of fossil logs within middle Miocene flood-basalt pillow lava complex - an examination of geological events and processes that created the "Vantage Forest" of central Washington State: EOS (Transactions of the American Geophysical Union), v. 72, no. 44, p. 602.

Beeson, M.H., and Tolan, T.L., 1990, The Columbia River Basalt Group in the Cascade Range - a middle Miocene reference datum for structural analysis: American Geophysical Union Journal of Geophysical Research, v. 95, no. B12, p. 19,547-19,559.

Beeson, M.H., Tolan, T.L., and Madin, I., 1989, Geologic map of the Lake Oswego quadrangle, Oregon: State of Oregon Department of Geology and Mineral Industries map GMS-59, scale 1:24,000.

Tolan, T.L., and Reidel, S.P., 1989, Structure map of a portion of the Columbia River flood-basalt province, in Reidel, S.P. and Hooper, P.R., eds., Volcanism and Tectonism in the Columbia River Flood?Basalt Province: Geological Society of America Special Paper 239, Plate 1, scale 1:500,000.

Tolan, T.L., Reidel, S.P., Beeson, M.H., Anderson, J.L., Fecht, K.R., and Swanson, D.A., 1989, Revisions to the estimates of the areal extent and volume of the Columbia River Basalt Group, in, Reidel, S.P. and Hooper, P.R., eds., Volcanism and Tectonism in the Columbia River Flood-Basalt Province: Geological Society of America Special Paper 239, p. 1-20.

Reidel, S.P., Tolan, T.L., Anderson, J.L., Beeson, M.H., Fecht, K.R., Bentley, R.D., and Hooper, P.R., 1989, The Grande Ronde Basalt, Columbia River Basalt Group - stratigraphic correlations in Washington, Oregon and Idaho, in, Reidel, S.P. and Hooper, P.R., eds., Volcanism and Tectonism in the Columbia River Flood-Basalt Province: Geological Society of America Special Paper 239, p. 21-53.

Reidel, S.P., Fecht, K.R., Hagood, M.C. and Tolan, T.L., 1989, Tectonic development of the central Columbia Plateau, in, Reidel, S.P. and Hooper, P.R., eds., Volcanism and Tectonism in the Columbia River Flood-Basalt Province: Geological Society of America Special Paper 239, p. 247-264.

Beeson, M.H., Tolan, T.L., and Anderson, J.L., 1989, Columbia River Basalt Group in western Oregon - geologic structures and other factors controlling flow emplacement patterns, in, Reidel, S.P. and Hooper, P.R., eds., Volcanism and Tectonism in the Columbia River Flood-Basalt Province: Geological Society of America Special Paper 239, p. 223-246.

Tolan, T.L., Anderson, J.L., and Beeson, M.H., 1989, Origin and characteristics of dextral strike-slip faults within the Yakima Fold Belt, Columbia River flood-basalt province, USA, in, Watters, T.R., and Golobek, M.P., eds., MEVTV workshop on tectonic features on Mars: Lunar and Planetary Institute Technical Report Number 89-06, p. 63-64.

Reidel, S.P., Fecht, K.R., and Tolan, T.L., 1989, Structural features of the Yakima Fold Belt, Columbia Plateau, central Washington - field guide for the Lunar and Planetary Institute MEVTV workshop, in, Watters, T.R., and Golobek, M.P., eds., MEVTV workshop on tectonic features on Mars: Lunar and Planetary Institute Technical Report Number 89-06, p. 83-124.

Beeson, M.H. and Tolan, T.L., 1987, Columbia River Gorge - The geologic evolution of the Columbia River in northwestern Oregon and southwestern Washington, in, Hill, M.L., ed., 1987, The Decade of North American Geology Centennial Field Guide, Volume 1 - Cordilleran Section of the Geological Society of America: Geological Society of America, p. 321-326.

Carson, R.S., Tolan, T.L., and Reidel, S.P., 1987, Geology of the Vantage area, south-central Washington - An introduction to the Miocene flood basalts, Yakima Fold Belt, and the Channeled Scabland, in, Hill, M.L., ed., 1987, The Decade of North American Geology Centennial Field Guide, Volume 1 - Cordilleran Section of the Geological Society of America: Geological Society of America, p. 357-362.

Anderson, J.L., Beeson, M.H., Bentley, R.D., Fecht, K.R., Hooper, P.R., Niem, A.R., Reidel, S.P., Swanson, D.A., Tolan, T.L., and Wright, T.L., 1987, Distribution maps of the stratigraphic units of the Columbia River Basalt Group, in, Schuster, J.E., ed., 1987, Selected papers on the Geology of Washington: State of Washington Department of Natural Resources, Division of Geology and Earth Resources Bulletin 77, p. 183-195.

Beeson, M.H., Tolan, T.L., Reidel, S.P., Fecht, K.R., Anderson, J.L., and Hooper, P.R., 1987, Jointing in the Columbia River basalt flows - association of jointing style with other factors: Geological Society of America, Abstracts with Programs, v. 19, no. 6, p. 358.

Fecht, K.R., Bjornstad, B.N., Reidel, S.P., Tolan, T.L., Anderson, J.L., Beeson, M.H., and Smith, G.A., 1987, Reconstruction of Neogene drainage systems in the area covered by the Columbia River Basalt Group: Geological Society of America, Abstracts with Programs, v. 19, no. 6, p. 376.

Anderson, J.L. and Tolan, T.L., 1986, Ages of wrench faulting in interridge basins, southwest Columbia Plateau, Washington and Oregon: Geological Society of America, Abstracts with Programs, v. 18, no. 2, p. 82.

Beeson, M.H., Fecht, K.R., Reidel, S.P., and Tolan, T.L., 1985, Regional correlations within the Frenchman Springs Member of the Columbia River Basalt Group - New insights into the middle Miocene tectonics of northwestern Oregon: Oregon Department of Geology and Mineral Industries, Oregon Geology, v. 47, no. 8, p. 87-96.

Tolan, T.L., Beeson, M.H., and Vogt, B.F., 1984a, Exploring the Neogene history of the Columbia River: Discussion and geologic field trip guide to the Columbia River Gorge, Part I, Discussion: Oregon Department of Geology and Mineral Industries, Oregon Geology, v. 46, no. 8, p. 87-97.

Tolan, T.L., Beeson, M.H., and Vogt, B.F., 1984b, Exploring the Neogene history of the Columbia River: Discussion and geologic field trip guide to the Columbia River Gorge, Part II, Road log and comments: Oregon Department of Geology and Mineral Industries, Oregon Geology, v. 46, no. 9, p. 103-112.