The pub dated back to the 1860s and drew its custom from Flash Street and Back Crook Street. But this was a heavily-pubbed area with something like 13 licensed premises in just a few hundred yards from what is now the fire station up to the junction with University Way.
Magee’s owned the Harp and they took the decision to close it in 1913. 
Alan Jenkinson writes on the Ancestry forum that his ancestor, John Helm, ran the pub from shortly before the 1911 Census until shortly afterwards which suggests he was probably the pub's last landlord.
The building later became a motor repair garage and remained in use for over 60 years. It was demolished in 1974 along with a number of other buildings on that row and the site was later developed to form a junction for part of the southern limb of Bolton’s inner relief road.
The photo at the top of the page shows the Harp garage, clearly marked, shortly before its demolition. Flash Street runs by the handwritten ‘No Parking’ sign. Further along, next to the white building is the former Old Three Tuns Hotel which opened in 1804 and closed in 1973. The Division One furniture store can be seen in the distance. The image is from the Bolton Library And Museums Service collection. Copyright Bolton Council.
 Bolton Pubs 1800-2000, by Gordon Readyhough. Published by Neil Richardson (2000).