Crag Lough was probably first discovered in 1907 by Marcus Beresford Heywood who recorded a number of routes in the Climbers Club Journal published in 1912. The article referred to five routes which are shown in a rather featureless diagram but from the descriptions it seems possible to identify what are now Hadrian's Chimney, Great Chimney and Main Wall. In the 1920's there were further visits by the next generation of climbers and though no doubt much was climbed nothing was recorded at that time. In the 1940s activity increased with a keen band of climbers including Basil Butcher, Keith Gregory and other members of what was to become the Northumbrian Mountaineering Club climbing many routes; by that time Pinnacle Face, Main Wall, Hadrian\'s Wall, Grad's Groove and the High Level Girdle Traverse were receiving regular ascents. Impossible Buttress and Route 1 was led by Tony Moulam giving possibly the hardest move on the crag at that time. In the 1950s the Crag Lough Club was formed and many harder routes were ascended including Crescent Crack, Y Climb, Why Not and Impossible Buttress Route 3.Further exploration continued into the 1960's but towards the end of that decade interest in the crag began to wane as increasing mobility among climbers brought the more distant sandstone outcrops into reach. Less frequent ascents have resulted in many obscure and some worthwhile climbs returning to a heavily vegetated state. The last routes of significance were added in the 1970's. Bob Hutchinson and John Earl made a rare diversion from the sandstone to free climb Smooth Bastion and rename it Whinstone Churchill, Jeff Lamb freed the previously aided Impossible Wall to produce the hardest route on the crag and Bob and Tommy Smith added the bold Stephenson's Rocket. In recent years there have been few, if any, worthwhile additions.
| 0 |  | Block Chimney, D | Andy Frazier |
| | With Phil Bains, Ian Applegarth |
| 0 |  | Y Climb, HVS 5a | Albert Rosher, Geoff Oliver |
| | with Frank Carroll and Don Laws |
| 1907 |  | Hadrian's Chimney, S | Marcus Beresford Heywood |
| | Originally called "Bloody Crack" |
| 1907 |  | Tarzan's Mate, VD | Marcus Beresford Heywood |
| | Details of this ascent come from the Climbers Club Journal of February 1912. The route has been tentatively identified from poor diagrams. See jere |
| 1907ish |  | Great Chimney, HS | Marcus Beresford Heywood |
| 1907ish |  | Main Wall, HS | Marcus Beresford Heywood |
| 1945ish |  | Route One, HVS 5a | Tony Moulam |
| | With Alf Mullan |
| 1945ish |  | Grad's Groove, MVS 4b | Brian Cooke, Bob Conn |
| 1945ish |  | Right Organ Pipe, HS | Tony Moulam |
| | with T P Snell, Gosman and other locals |
| 1945ish |  | Left Organ Pipe, HVS 5a | Tony Moulam |
| | with T P Snell, Gosman and other locals |
| 1945ish |  | Helix, S | Tony Moulam |
| | With T P Snell, Gosman and other locals |
| 1945ish |  | The Stone Warrior, E1 5b | Tony Moulam |
| | With T P Snell, Gosman and other locals |
| 1947 |  | The Girdle Traverse, VS 5a | Brian Cooke |
| | Assumed to be Brian, as he wrote the route up in the first NMC newsletter here |
| 1950ish |  | Sciatica, VS 4c | Albert Rosher, Geoff Oliver |
| 1955ish |  | Route Three, VS 5a | Albert Rosher, Geoff Oliver |
| 1955ish |  | Crescent Cracks, VS 5a | Albert Rosher, Geoff Oliver |
| | And Frank Carroll + Don Laws |
| 1955ish |  | Why Not, VS 5a | Albert Rosher, Geoff Oliver |
| | (With Frank Carroll and Don Laws) |
| 1955ish |  | Centurion's Crack, S | Tony Moulam |
| | With T P Snell, Gosman and others |
| 1960ish |  | Neglect, HVS 5a | Nev Hannaby |
| 1970ish |  | Impossible Wall, E4 6b | Jeff Lamb |
| 1976 |  | Whinstone Churchill, E2 5b | John Earl, Bob Hutchinson |
| 19 August 1978 |  | Brutus, HVS 5b | Tony Marr, Ken Jackson |
| 1979ish |  | Intermediate Treatment, E2 5c | Callum Phillips, Steve Lude |
| 1979ish |  | Sweet Violets Bitter Almonds, D | A. Hedgecock, D. Brown |
| 1979ish |  | Chariot Race, E3 5c | Jeff Lamb |
| 1979ish |  | Helix Direct, HVS 5a | Steve Lude, Callum Phillips |
| 5 May 1980 |  | Stephenson's Rocket, E4 5c | Bob Smith, Tommy Smith |
| 1981 |  | Jane, MVS 4c | Tony Griffiths, Mick Harris & Nick Prior |
| 4 June 1981 |  | Wooden Tops, E1 5b | Bob Smith, Tommy Smith |
| 4 June 1981 |  | Spot the Dog, HVS 5b | Bob Smith, Tommy Smith |
| 3 September1991 | | Direct Start, 5c | Hugh Harris, Rhian Webb |
| 1 April 1999 |  | God Lives Under Water, E2 5b | Mark Savage, Neil Anderson |