Across:
   1. Party abandoned stevedore on strike, something many parties have abandoned (7)
   5,18. Geographic feature mixing a river and sea (6 6)
   9. Peak fitness used, just in starts (4)
  10. Some junk now a blessing, which could not have been anticipated (10)
  12. Religion from land of 9 thus holding clue (6)
  13. Most green at selfie composition (8)
  14. MAGA pride mostly wrecked model (8)
  16. Arrangements for returning special tradies' vehicles (6)
  18. see 5
  20. Not missing... not given decoration! (8)
  22. Royal put out a Hail Mary adaptation... which is big in Asia (8)
  24. Quantity of pilau tirelessly turned in ceremony (6)
  26. Foolish errant moth's fatal attraction? (10)
  27. Premium slopes regularly providing destination for many skiers (4)
  28. Check city as browser (6)
  29. Some boxers, which are big in America (7)
Down:
   2. Have focus restored for Grant (9)
   3. When love is lost, recklessly ignore rule (5)
   4. Lad and I catch puma (almost) for dessert (7)
   6. The pressure's the same along such lines where you drink alone? (7)
   7. Endure A-list "icons", not entirely lifelike (9)
   8. Big range in Africa with a last 19 (5)
  11. Fire arm OK in jail? It's very prominent! (11)
:  15. Torture for 8: bear soft rock! (9)
  17. Fruit of long program with the French (9)
  19. A rearrangement? Re-enter text when mixed up with this! (7)
  21. Root not developed; it must be cold here (7)
  23. Back in America, Asimov's name! (5)
  25. Kid's first cart going around circuit (5)
Solution:
EVEREST=SIERRA=|
=O=E=P===S=E=T=|
FUJI=UNKNOWABLE|
=C=G=M=I=B=L=A=|
SHINTO=LEAFIEST|
=S===N=I=R=S===|
PARADIGM=SETUPS|
=F=L===A===I=I=|
NEVADA=NOTICING|
===B=N=J=O===E=|
HIMALAYA=RITUAL|
=S=S=G=R=O=R=P=|
MATTERHORN=ALPS|
=A=E=A===T=C=L=|
=CHROME=ROCKIES|
Name: 858 - Peak Fitness
Author: by BenDR