Columbia Point dGNSS Survey– Removed from Centennials List
Eric Gilbertson, Elijah Gendron, Ben Loftin
Summary – Columbia Point has 299.6ft of prominence, which is below the 300ft cutoff to be ranked. Thus, Columbia Point should be removed from the Centennials list.
Lidar measurements of Columbia Point and its key col measured the prominence within error bounds of the 300ft cutoff. A ground survey was necessary to determine the prominence with sufficient accuracy to determine if the peak has enough prominence to be ranked.
On October 4, Eric took ground measurements using professional surveying equipment on the summit and key col. This equipment is capable of sub-inch vertical accuracy. He used a Trimble DA2 dGNSS receiver mounted on the summit and col (verified with an Abney level) and took one hour of data at each location.
We processed data with three different methods -TrimbleRTX Centerpoint, TrimbleRTX Surveytools, and CSRS-PPP. We converted all results to identical horizontal and vertical datums (NAD83(2011) Epoch 2025.7 NAVD88 Geoid18).
All results were consistent that the prominence is 299.6ft. Confidence is calculated as >99% that the prominence is less than 300ft. See detailed report at https://www.countryhighpoints.com/columbia-point-survey/
Eric has a PhD in mechanical engineering from MIT and is a teaching professor at Seattle University teaching mechanical engineering and civil engineering courses, including courses specific to mountain surveying. He has surveyed over 60 peaks around the world, discovering new country highpoints in six countries (Saudi Arabia, Colombia, Uzbekistan, Togo, Guinea-Bissau, and Gambia) recognized by local governing bodies like the Saudi Climbing Federation. He discovered that Mt Rainier has melted down over 22ft, and his work has been published in academic journals like Arctic, Antarctic, and Alpine Research Journal and newspapers like Seattle Times. He has climbed the highest peak in 147 countries.
We would propose that anyone who has already completed the Centennials or another list including Columbia Point is grandfathered in and still considered a finisher. Moving forward, this means Niagara Peak, formerly considered the 101st tallest peak in Colorado based on LiDAR, should be added to the Centennials list. The current order of peaks near the cutoff for inclusion by elevation based on LiDAR-derived summit elevations is now Peak 13820 (#97, 13,820ft), Arrow Peak (#98 13,817ft), Trinity Peak (#99 [tie], 13,816ft), Niagara Peak (#99 [tie], 13,816ft), Teakettle Mountain (#101, 13,815ft), American Peak (#102, 13,814ft), Dallas Peak (#103 [tie], 13,812ft), Obstruction Peak (#103 [tie], 13,812ft). Given that we have previously measured errors up to 3.1ft in LiDAR-derived summit elevations for above-treeline peaks in Colorado (for Crestone Peak), a conservative error bound would be +/-4ft on any of these elevations. This means all eight of these peaks are edge-case peaks. Only four of these eight are true Centennials, and the other four are too short to qualify. Future work includes surveying each of these edge case peaks with dGNSS surveys. Until that is completed, it will not be known for certain which are Centennial Peaks. Accuracy-minded mountaineers could climb all eight to be certain to have completed the list.
Link to detailed report: https://www.countryhighpoints.com/columbia-point-survey/