There and Back Again

solution
THERE
1. Roofing material
6. Roy G. Biv, e.g.
14. Hit with alphas or betas
24. Water-hoarding plants
30. Hip bone (Br.)
36. In _ (pre-natal state)
41. Tactile cipher
49. Eat away
54. Two ups and one down
61. Popular hitch
66. Method of preparing cow skin
73. Hirschfeld scribble
77. Express, in acting
83. Ivy and oak third
88. To the rear of a ship
93. Cuban dance

BACK
100. Center of an amphitheater
95. One hundred satang
90. Manilla hemp source
85. Revolutionary firearm
78. Something RHPS lacks
70. Inherent
64. Crust fissure
57. Mark 50, e.g.
50. Often done with broadcast rights
43. Forest Hills destination
33. Contrary to law or convention
26. Signature style
20. 1871 premiere
15. A reason to avoid castor oil
10. Portent
6. Transition elements, among others