1. The "A" of MoMA → ART
2. Seaweed wrap for maki → NORI
3. Secluded valley → GLEN
4. Some info sheets → LEAFLETS
5. Radical → EXTREME
6. One doing stellar work? → ASTRONOMER
7. Golfer's warning → FORE
8. Regretted → RUED
9. Major oil cartel, in brief → OPEC
10. "Bravo!" → NICELYDONE
11. Blatant → OVERT
12. Flat-topped landforms → MESAS
15. Full range → GAMUT
20. Tinder account datum that can't be edited → AGE
21. The Hundred ___ Wood (storybook setting) → ACRE
24. Post to an online journal → BLOG
25. Org. for seniors → AARP
26. Advances from third while the pitcher is distracted, say → STEALSHOME
27. What team-building activities are designed to build → TRUST
28. Noodle that might be stuffed → PASTASHELL
29. Dined → ATE
33. Actor Wilson → OWEN
34. "Frozen" queen → ELSA
36. Suffix with lemon or stock → ADE
37. Slow-cooked taco filling → BARBACOA
39. "___ just me, or …?" → ISIT
40. Rigorously demanding sort → HARDASS
42. Nautical greetings → AHOYS
43. "Gosh!" → GEE
44. Popular hummus brand → SABRA
45. Run-of-the-mill → USUAL
48. Rae of "Barbie" → ISSA
49. Inexperienced gamer, informally → NOOB
50. Factual → TRUE
51. What "maki" means in Japanese → ROLL
52. Kardashian matriarch → KRIS
56. Contract enforcing secrecy, for short → NDA