Here is my list:
GC5B Phil's Memorial Cache (Oldest CA. Cache) (2016-01-28) 8979 days
GC5F Yuba City (2014-06-29) 8965 days
GC78 Firestone (2013-03-04) 8957 days
GC9C Rabbit Eye View (2013-12-29) 8932 days
GC111 Napa County's First Geocache (2013-01-20) 8874 days
GC79E Rock Face (2015-03-07) 8755 days
GC1686 Plank's Resting Place (2022-07-17) 8647 days
GC1735 Road Trip (2014-08-30) 8637 days
GC1980 Disneyland Geocaching (2019-10-15) 8629 days
GC1C2A NYFGBA CNEX (aka Stickers In My Socks) (2013-02-10) 8615 days
GC1FD2 Crow's Loop (2022-02-12) 8594 days
GC22F7 The Selkirk Cabin (2023-04-29) 8578 days
GC2625 SierraHeights (2014-07-20) 8560 days
GC2710 Elk Grove (2015-10-22) 8555 days
GC2B83 Skippy (2012-11-25) 8527 days
GC33F5 Big Critters With Antlers (2014-08-14) 8482 days
GC36E3 TONS OF FUN TWO (2014-08-14) 8469 days
GC36DF TONS OF FUN ONE (2014-08-14) 8469 days
GC38AC Help! I'm Falling! (2006-01-13) 8462 days
GC3926 Chili Gulch (2015-07-24) 8461 days
GC3CBB Where's Waldo (2015-02-21) 8448 days
GC3F64 Electric Horseman (2013-08-15) 8440 days
GC4140 Don't Panic (2019-07-24) 8433 days
GC42A2 Hill Top Lookout (2010-02-15) 8427 days
GC456D Captain Hook (2014-10-12) 8419 days
GC4797 Rockville Stinger (2006-01-13) 8412 days
GC4B24 WD's Original (2019-10-15) 8404 days
GC57FA Out Of Africa (2013-08-07) 8377 days
GC62C3 Four Corners (2014-07-27) 8342 days
GC674C Lena's Place (2015-07-24) 8329 days
GC6B91 Fossil Find (2023-05-06) 8319 days
GC6C6C California Dreaming (2013-01-13) 8317 days
GC6CCE Omo i de (2013-02-07) 8316 days
GC6CCD Clang Clang - Vacaville History (2013-02-06) 8316 days
GC7BFE The Center (2014-04-14) 8282 days
GC7CE1 Silver Gyrations (2013-09-08) 8281 days
GC8234 Knott's Berry Farm Ghost Town (2018-10-20) 8270 days
GC8912 Mono's Pioneers (2014-07-20) 8258 days
GC94A4 Drunken Sailor (2012-11-13) 8231 days
GC97A3 The Sunshine Express (2016-01-26) 8224 days
GC98C2 Working Capitol (2010-12-03) 8222 days
GC9A43 Cricket's Reflection (2020-10-12) 8218 days
GC9CCF Fishfull Thinking @ Tom's Place (2014-07-19) 8217 days
GC9B89 Can You Hear Me Now? (2013-04-01) 8216 days
GC9EBA Jolly Old..... Stockton?????? (2015-07-28) 8209 days
GCA2A6 Putt's Historical Marker Cache (2015-07-24) 8199 days
GCA462 In the 'City of Trees' (2013-09-28) 8195 days
GCA481 Bit of History (2020-07-01) 8194 days
GCA7A1 Holy Moley Batman! (2015-12-31) 8192 days
GCAA46 A Quiet Corner (2013-03-27) 8181 days
GCA99C Skyline Virtual (2013-04-14) 8181 days
GCAC5F Monument (2014-12-13) 8175 days
GCACF5 Disney California Adventure (DCA) Benchmarks (2015-11-16) 8174 days
GCB155 Vatican I (2016-01-27) 8165 days
GCBA31 Human Powered Flight (2016-01-26) 8141 days
GCBFA9 Herman's Mahem (2012-07-14) 8132 days
GCC044 Fresno Flats (2017-07-21) 8131 days
GCC0E8 A Basic Virtual (2012-10-10) 8130 days
GCC3AF Poor Fluffy... (2013-09-28) 8125 days
GCC92A Stone's Turnpike (2022-01-23) 8117 days
GCC895 Fire One! (2013-03-08) 8115 days
GCCD52 A walk in the park (2012-01-25) 8106 days
GCCE37 Cooperstown Bridge (2015-12-31) 8105 days
GCD018 What a Sight! (2013-03-22) 8102 days
GCD530 Camel Cavalry Cache (2012-11-14) 8091 days
GCD529 Old Gray Mare (2013-03-10) 8091 days
GCD748 Wilton Memorial Rose Garden (2015-10-26) 8088 days
GCD8F8 Hey Buddy, gotta light? (2013-09-12) 8085 days
GCDC11 Sonoma Sojourn (2014-04-14) 8079 days
GCDD2D Get Out and Walk! (2011-03-16) 8077 days
GCDFE3 Busy Boothill (2016-04-08) 8072 days
GCE204 ZERO DECLINATION (updated) (2013-04-04) 8069 days
GCE6C7 HUMPHREY (2013-08-07) 8062 days
GCEECF Big Pine Triangle County Park Virtual (2014-07-19) 8049 days
GCEF85 Another Quiet Corner in Benicia (2013-02-05) 8048 days
GCF095 Place of Honor (2014-06-29) 8047 days
GCF488 Snooping at the CIA (2014-08-01) 8042 days
GCFED7 Winters' Shaker of 1892 3/3 (2013-03-07) 8038 days
GCFEC3 Winters' Supreme Sacrifice 2/3 (2013-03-07) 8038 days
GCFEC7 Walking In A Winters' WaterLand 1/3 (2013-03-07) 8038 days
GCC745 Got Milk!!! (2012-10-21) 8035 days
GCFC24 Sky Park (2016-01-26) 8029 days
GCFC15 Uncle Burt (2011-12-09) 8029 days
GCFF1A Snell Station (2021-10-29) 8026 days
GCFF93 Laguna Rose Garden (2015-10-10) 8025 days
GCG0MZ Northbound I-5 "PIT" Stop (2012-10-06) 8021 days
GCG65D MARK'S not a STUMP (2011-06-18) 7991 days
GCG926 Disney's Horseshoe Review (2019-10-13) 7977 days
GCGED5 Mothball Vista Vista (2005-12-30) 7946 days
GCGFXY The Hidden Dragon (2014-07-19) 7937 days
GCGH00 Napa's History #1 (2014-07-12) 7932 days
GCGGXA Historic Crossroads Murals (2014-09-05) 7932 days
GCGHVE Flying Weeds (2011-01-04) 7930 days
GCGHWB Iguana's Lunch (2014-02-18) 7928 days
GCGJ53 Original McDonalds - McToy Museum (2016-01-27) 7926 days
GCGKRH Grape of the Basevine (2015-02-05) 7918 days
GCGTHP Country Drive / Country Inn (2013-02-11) 7893 days
GCGXER Owens Valley History (2014-07-19) 7877 days
GCG9WZ Jack sat here (2013-03-27) 7866 days
GCE0F1 Shalom! (2023-05-13) 7860 days *archived*
Total age for 100 oldest caches is 824026 days of 766500 required.