An "approach" is typically a foot access to a certain peak or group of peaks where the "route" up the peak is considered to begin. Most of our "approaches" involve a backpack of some distance and the establishment of a base camp from which several peaks may be climbed. In some cases, an "approach" may be a trail access to a specific location where you can branch off in different directions for two or more summits, usually done as day hikes.
In a "sequence" of peaks where two or more are climbed together and usually each is accessed by a connecting ridge, the route to a previous peak in the sequence will become the "approach" for the next summit.
G&JR refers either to Gerry and Jennifer Roach and/or their book, "Colorado's Thirteeners" which covers thirteen thousand foot summits from 13,999 to 13,800 ft. in elevation. Gerry Roach, a climber/mountaineer of international status and Jennifer Roach, one of the pioneering women to have climbed all of Colorado's 13ers, have combined their knowledge into this detailed and useful book for 13ers ranked from #54 to #106. Still in print, it is a "must-own" for serious peakbaggers. Includes extensive trailhead, approach and multiple route information.
G&M stands for the book co-authored by Mike Garratt and the now deceased Bob Martin. Book name is "Colorado's High Thirteeners," A Climbing and Hiking Guide. The book is out of print but was a "climber's Bible" for several decades, having been first published in 1984? The book covers 13ers ranked from #54 to #200.
GCM refers to a book first authored by Robert M. Ormes, considered one of the "grandfathers" of Colorado mountaineering. Subsequent editions were taken over by the CMC (Colorado Mountain Club).This is another "climber's bible" which covers mostly named summits located in every mountain range of Colorado. The route descriptions and approaches are stated succinctly. It is still in publication and with updates added to the 10th edition, is extremely useful for Colorado peak information.
LoJ stands for www.listsofjohn.com, a website belonging to John Kirk that exists primarily for climbers to register their ascents. This site lists summits not only for Colorado, but numerous other states, allows registrants to build custom lists, post trip reports and view the ascents of other climbers. Highly recommended for recording your personal climbs.
RT = round trip. Approach mileages are usually presented as round trip. In a sequence of peaks, the RT mileage for the first summit will be to that summit alone and back to the trailhead or end of approach. For all other summits in the sequence, the RT mileage will assume completion of the circuit. Starting and ending point will be the same.
As we use this term in this site a "sequence" of peaks is when two or more summits are climbed together, usually by connecting ridges or common terrain that allows easy access to each summit in the sequence. When this happens the "round-trip" route mileage will be displayed as the same for each summit in the sequence and the "one-way" mileage and elevation gain will be measured from each previous summit. There are a large number of sequenced peaks on this site. They do not have to be climbed as we did. Our sequenced routes are only a suggestion, but you have the assurance they were climbed as we have outlined.
SJM stands for a book by Robert F. Rosebrough and Matt Payne titled, "Climbing Colorado's San Juans: A Comprehensive Guide to Hikes, Scrambles and Technical Climbs." This book has been (there was a previous version published in 1986) and continues to be a useful guide to important summits located in the San Juan Range, providing both trailhead, approach and route details. We highly recommend this book for the San Juan summits.
TH stands for trailhead. A trailhead is usually where vehicle access ends and foot access begins. In some cases, it may indicate the end of access for all but 4WD vehicles, which may be able to continue for additional distance reducing foot travel.