| | | 2038 |
| Jacinda | Greenwood | A forest guide in Greenwood Arboreal Cathedral. Protagonist. |
| Knut | | The most senior forest guide. Jake's closest friend. |
| John | Muir | An advocate of U.S. conservation. |
| Torey | | A young guide. |
| Davidoff | | A Russian special forces operative. Jake's boss. |
| Corbyn | Gallant | The celebrity pilgrim. Jake's client. |
| Meena | Bhattacharya | A first chair violist. Jake's mother. |
| Liam | Greenwood | Jake's father. Willow's son. |
| Dr. | Biswas | A leading expert on bodhi tree. |
| | | General Sherman - The world's biggest tree. |
| Harris | Greenwood | The owner of Greenwood Island. |
| Willow | Greenwood | Harris's daughter. Jake's grandmother. |
| R.J | Holt | The founder of Holtcorp. |
| John | Rockefeller | The Greenwood Island's former owner. |
| | | 2008 |
| Alvarez | | Liam's helper. |
| Temple | Van Horne | Liam's great-aunt. |
| George | Nakashima | A master woodworker. |
| Tanya | Petrov | An oil oligarch's wife. |
| | | 1974 |
| Sage | | Willow's ex-lover. |
| Everett | Greenwood | Willow's uncle. Harris's brother. Aka: Saul Bowater. |
| Liam | Feeney | Harris's translator. |
| | | 1934 |
| Harvey Bennett | Lomax | Mr. Holt's driver. |
| Euphemia | Baxter | One of Mr. Holt's employees. |
| Lavern | Lomax | Harvey's wife. |
| Harvey | Lomax Jr. | Harvey and Lavern's son. |
| Hattie | Lomax | Harvey and Lavern's daughter. |
| Howard | Blank | A war veteran. Everett's companion. |
| Pee-wee | Morton | Everett's acquaintance. |
| Mort | Baumgartner | One of Harris's colleagues. |
| H.R | Macmillan | A timber syndicate leader. |
| Terrance | Milner | Harris's long-time clerk. |
| Fiona | Craig | Harris and Everett's guardian. |
| Sinclair | Monahan | The buggy driver. Everett's boss. |
| Mrs. | Papadopoulos | Pod's babysitter. |
| Art | McSorley | A railroad detective. |
| Pod | | The baby that Everett finds. |
| | | 1908 |
| James | Craig | Fiona's husband. A physician. |
| Parson | Brennan | Mrs. Craig's companion. |
| Taisto | Maki | The town's famous woodcutter. |
| Ms. | Miller | Harris and Everett's teacher. |
| Doc | Kane | Mrs. Craig's doctor. |
| Sam | Sharpe | A Lt. Colonel. Harris's boss. |
| Gilles | Thibault | The headmaster of the deaf and blind academy in Montreal. |
| | | 1934 |
| Gertie | | Temple's cook. |
| Jurgen | Kohler | Temple's husband. |
| Bennett | | The prime minister. |
| Cook | | The ship captain. |
| | | 1974 |
| Frederick | Weyerhaeuser | The deceased lumber king. |
| | | 2008 |
| Orin | | Liam Greenwood's friend. |