Depending how you count a separate peak, Colorado has 53-58 peaks over 14,000 feet, the so-caller "14ers". It seems a natural challenge to attempt to climb all these lofty summits over some period of time -- most people would accept a lifetime as a reasonable goal. Of course, for some it is irresistable to see just how quickly they can bag the lot.
How many 14ers are there? For purposes of the record, at least through Cave Dog's record in 2000, people used 54-55 peaks. They are the 53 peaks having a minimum of 300' prominence (as listed on Wikipedia, note that Challenger Point was only named in the 1987), plus the traditionally accepted summits North Maroon and El Diente. More recently, it has become popular to say that there are 58 14ers. None of the 3 added peaks (points, really: North Eolus, Cameron and Conundrum) meet the 300' prominence rule. Nevertheless, in recent years it seems like the community has come to accept the list of 58, which are all points over 14,000' which have official names according to the USGS, as shown to the right. Hopefully the USGS will not go on a naming spree!
Several guide books and a website are dedicated to the 14ers. The 14ers have become so popular that erosion and trail damage became a problem. The Colorado Fourteeners Initiative was formed in 1994 to maintain these routes and protect the fragile alpine environment of these peaks.
The 14ers are scattered all over the state, and it is standard to use vehicles to shuttle between the trail heads. You can actually drive to the summit of some of the 14ers (particularly Pikes Peak and Mount Evans). So, over the years some rules of engagement have been established for viable 14ers records. Most critical is the so-called "Colorado Rule", which says that the climber must ascend at least 3,000 vertical feet net elevation on foot from the base of the first peak in a series, and descend at least 3,000 feet at the end of the series. The climber may descend less than 3,000 feet when traversing between peaks that are linked on foot. Cave Dog's website gives a detailed discussion of the rules and some intricacies. In particular, Cave Dog established the so-called "no guiding" rule. Under this rule, the record aspirant may have company, but must be out front at all times and must do all the route finding.
There have been many amazing speed records on the 14ers going back nearly 50 years. As the record has evolved, so has the list of recognized 14ers. Lately, record aspirants have gone after 58 peaks, which are all points over 14,000' that have officially-recognized names (by the USGS), as discussed here. Cave Dog's website gives an excellent discussion (by Rick Trujillo) of the history of speed records on the 14ers. To give a sense of the challenge, for their 1997 record (14d0h16m), Rick Trujillo and Ricky Denesik calculated that they traversed a total of 314 miles and gained 153,215 vertical feet! Here's a summary of historical speed records from Cave Dog's site:
1960, Cleve McCarty climbed the 52 recognized 14ers in 52 days.
1974, George (father), Flint, Quade, Cody, and Tyle (sons) Smith ("The Climbing Smiths"), climbed 54 14ers in 33 days (and established the 3000' rule).
1976, Steve Boyer climbed 54 14ers in 22 days.
1980, Dick Walkers climbed 54 14ers in 18d15h40m.
1990, Quade and Tyle Smith climbed 54 14ers in 16d21h35m.
Up to 1990 all records were essentially self-sufficient. The following records were set with the aid of support crews.
1992, Adrian Crane climbed 54 14ers in 15d17h19m.
1993, Jeff Wagener climbed 55 14ers (adding Challenger Point) in 14d3h.
1995, Rick Trujillo and Ricky Denesik climbed 55 14ers in 15d9h55m (fast, but not a record).
1997, Ricky Denesik climbed 55 14ers in 14d0h16m (Trujillo started with Denesik, but stopped after 39 peaks).
August-September 1999, Andrew Hamilton cimbed 55 14ers in 13d22h48m.
July-August 2000, Ricky Denesik reclaimed the record for 55 14ers, 12d15h35m.
July-August 2000, Danelle Ballengee set the female record for 55 14ers, 14d14h49m.
September 2000, "Cave Dog" Ted Keizer set the final record for climbing 55 14ers, 10d20h26m.
June-July 2015, Andrew Hamilton finally beat Cave Dog's records, climbing 58 14ers in 9d21h51m.
Another history of 14ers speed records, including some earlier records, was posted to 14ers.com in 2014. A few of the details are different from those given above.
Winter: Only a few people have climbed all the Colorado 14er in wintertime, and until 2018 no one had completed all 58 during a single calendar winter. Will Seeber climbed 51 summits during the winter of 2016-2017, which was at that time the most climbed in a single winter. As usual, Seeber's project was followed on 14ers.com, and this long thread includes an in-depth discussion of what might constitute winter "rules" for a Colorado 14ers speed record - there are many nuances that may differ from the better-established summer "rules" followed by Andrew Hamilton and others. In summary it appears that the community has not yet come to consensus on winter "rules". It is of note that Seeber was more or less "self-supported" in that he had no designated support crew, though he often climbed with others. He sometimes used skis or snowshoes, and rode a bicycle to the top of Pikes Peak. His peak list for the season is given here. [NOTE: For some reason people have added "North Massive" to the winter list, making it 59 peaks.]