The Sinister Signpost
| Publisher | Grosset & Dunlap |
| Series | Hardy Boys Mystery Stories |
| Format | Hardback |
| Language | English |
| Location | New York |
| Copyright | 1968 |
| Pages / Font | 175 pages |
| ISBN | 0-448-08915-7 |
| Library of Congress Classification Number | 68-15296 |
| Series Number | 8915 |
Added by jlkrien