K-37 locomotives were originally built as standard gauge Denver & Rio Grande Class 190 units in 1902.  During the big renumbering/reclassing of 1924, the units became Class C-41.  Between 1928 and 1930, the D&RGW's own Burnham Shops rebuilt these units into the narrow gauge K-37 class.
| Unit | Mfgr. | Model | Serial | Built | Notes | 
|---|
| 490 | Baldwin | K-37 | 20695 | 1902 | Built as D&RG Class 190 1114 Renumbered 1924 to D&RG Class C-41 1014
 Rebuilt by Burnham Shops to K-37 490 in 1928
 Retired 1962, dismantled 1963-1964
 Smokebox to 492, cab in DSNG yard at Hermosa, CO
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| 491 | Baldwin | K-37 | 20829 | 1902 | Built as D&RG Class 190 1126 Renumbered 1924 to D&RG Class C-41 1026
 Rebuilt by Burnham Shops to K-37 491 in 1928
 Got 496's tender, then to 494
 Got 499's tender at CRRM
 Property of Colorado Historical Society
 On long term loan to Colorado RR Museum
 Only K-36 with thermic syphons, reportedly making it one of the best K-37s to run
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| 492 | Baldwin | K-37 | 20749 | 1902 | Built as D&RG Class 190 1121 Renumbered 1924 to D&RG Class C-41 1021
 Rebuilt by Burnham Shops to K-37 492 in 1928
 Rebuilt with smokebox parts from 490 after striking rock near Navajo, NM, on 6-Aug-1963
 To C&TS in 1970, static display Chama, NM
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| 493 | Baldwin | K-37 | 20550 | 1902 | Built as D&RG Class 190 1105 Renumbered 1924 to D&RG Class C-41 1005
 Rebuilt by Burnham Shops to K-37 493 in 1928
 Retired 1970, to DSNG Mar-1981, static display Silverton, CO
 Moved to Durango 4 May 2016 for possible lease to CRRM, didn't happen
 Converted to oil burner and returned to service as DSNG 493 on 24 Jan 2020
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| 494 | Baldwin | K-37 | 20748 | 1902 | Built at D&RG Class 190 1120 Renumbered 1924 to D&RG Class C-41 1020
 Rebuilt by Burnham Shops to K-37 494 in 1928
 Original tender to 498
 Current tender ex-491,exx-496
 Retired 1962, to C&TS in 1970
 Static display at Antonito, CO
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| 495 | Baldwin | K-37 | 20522 | 1902 | Built at D&RG Class 190 1104 Renumbered 1924 to D&RG Class C-41 1004
 Rebuilt by Burnham Shops to K-37 495 in 1928
 Retired 1962, to C&TS in 1970
 Static display at Antonito, CO
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| 496 | Baldwin | K-37 | 20751 | 1902 | Built as D&RG Class 190 #1123 To D&RGW Class C-41 #1023 1924
 Rebuilt to K-37 #496 1930
 Retired on account cracked boiler
 Tender to 491, rest scrapped Pueblo 1955
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| 497 | Baldwin | K-37 | 20521 | 1902 | Built at D&RG Class 190 1103 Renumbered 1924 to D&RG Class C-41 1003
 Rebuilt by Burnham Shops to K-37 497 in 1930
 To DSNG Mar-1981, traded to C&TS 1991 for K-36 482
 Stored servicable - flue time expired end of 2003
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| 498 | Baldwin | K-37 | 20640 | 1902 | Built at D&RG Class 190 1109 Renumbered 1924 to D&RG Class C-41 1009
 Rebuilt by Burnham Shops to K-37 498 in 1930
 Received "flying RG" logo ~1940
 To DSNG Mar-1981, static disp Durango, CO
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| 499 | Baldwin | K-37 | 20753 | 1902 | Built at D&RG Class 190 1125 Renumbered 1924 to D&RG Class C-41 1025
 Rebuilt by Burnham Shops to K-37 499 in 1930
 Retired by DRGW 1970, to DSNG Mar-1981
 Traded to Royal Gorge for 486 in 1999
 Orig tender to 491 at CRRM
 Current tender ex-498,exx-494
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