Celebrating 100 Years of the Rocky Mountain Association of Geologist
Authors: Jackson Jane E. , Anderson Donna S. , Silverman Matthew R. 
Published: June 2023

In 2022, the Rocky Mountain Association of Geologists (RMAG) celebrated its centennial anniversary. Founded on January 26, 1922, RMAG (called Rocky Mountain Association of Petroleum Geologists until 1947) grew out of a desire and need for petroleum geologists in Denver to come together in a collegial environment. Petroleum geology had become an important component of exploration and development, with significant discoveries in the greater Denver Basin (Florence Field) as well as east-central Wyoming (Salt Creek Field) and northwest Colorado (Rangely Field). Through the first 25 years (1922–1947), membership hovered around 50, reflecting an initial boom of World War I through the 1920s, and then surviving the Great Depression and World War II. Post-World War II through the early 1980s, the world saw a huge increase in demand for oil (less-so for natural gas), spurring the “golden years” of Rocky Mountain exploration and development of many now-famous discoveries. Denver grew as a petroleum business center with large (major) to small (independent) companies, leading to steady RMAG membership growth, which peaked at 4,524 in 1984. During this period, RMAG established a legacy of publishing (The Mountain Geologist and the Geologic Atlas of the Rocky Mountain Region, aka “the Big Red Book”), sponsored multi-day field trips and symposia, hosted weekly luncheons with 200–300 attendees at the peak, and maintained a dedicated office staff located in downtown Denver. The legacy “golden” years ended with the “crash” in oil prices in 1985–86, and membership declined about 7% per year until the mid-1990s, levelling out at 1,900 members. Within the ashes of the 1984–1995 period, however, RMAG began its On the Rocks field trip series (1986) and published several sold-out guidebooks. It inaugurated the 3D Seismic Symposium (1995) co-hosted with the Denver Geophysical Society (DGS) and hosted several successful AAPG and Rocky Mountain Section AAPG annual meetings. In the 1990s, natural gas hosted in “unconventional” reservoirs began an exploration/development revolution, spurred on by federal price supports and construction of a major gas pipeline to the West Coast in 1992. By 2000, huge natural gas resources locked in Rocky Mountain “tight gas” reservoirs became economically viable with improved hydraulic fracturing technology and increasing gas prices. RMAG membership began growing along with the increased natural gas-drilling activity, and RMAG offered multiple well-attended symposia and publications highlighting unconventional gas plays. A new boom began in 2008 with the advent of horizontal drilling for oil in the Bakken Shale of the Williston Basin and Niobrara Formation of the Denver Basin, and a massive increase in oil price. Consequently, RMAG membership reached a secondary peak of 2,978 in 2012. However, as oil prices began declining steadily in 2014, membership also decreased. By 2016, oil price decline led to the familiar cycle of company closings and layoffs. In 2020, the Covid-19 pandemic shut down all in-person RMAG activities, heavily impacting the organization. RMAG pivoted to online (virtual) luncheons, symposia, and field trips. Even so, membership declined to about 1200 members in 2022. The challenges that the RMAG will face in the next 100 years will be daunting. Long-term sustainability of the RMAG will require its members and member-leaders to recognize and embrace changes as they occur.