Leasing of the land and tower properties to unrelated third parties were rental activities as defined in Sec. 469.
Passive income is most commonly reflected on Schedule E as a net rental income.
Examples: fields leased to a farmer, mobile home parks, land leased for billboards, lots leased to sell Christmas tree, land leased for cell towers and campgrounds.
https://www.irs.gov/Businesses/Small-Businesses-&-Self-Employed/Passive-Activity-Loss-ATG-Chapter-3-...
