The area where The Mount now is was 'a large open place' called Gelding Hill. Here boys played cricket, the circuses that visited were held as were poultry fairs .
A meeting of the Malton Local Board of Health in April 1860 approved the plans submitted for one of two houses to be built on the Gelding Hill by Mr. R. Stabler 
Looking at the advertisements on this page, and in the context of a 99 year lease, it is possible to deduce that most of the houses were built in the mid to late 1860s. Descriptions in the advertisements reveal that from the outset the area was positioned as a 'well to do' area - potentially for the wealthy professionals and tradesmen of the town.
No 21 The Mount This was completed in 1864. See the 1952 sale catalogue describing this property. Paul Hickes, a retired draper, was the original purchaser in 1864.
No 25 The Mount, Fern Croft, was advertised for sale in the Malton Messenger of 6 May 1922 as being for many years in the occupation of Mrs. Charles Russell. A full description of the accommodation is given and the house was said to be lighted by gas and leasehold, under the Earl Fitzwilliam for a term of which 34 years are unexpired at April 6th this year.
-  Russell's Malton, Norton & District Almanac & Diary, 1888
-  Malton Messenger, 28 April 1860
Properties for Sale
CLAREMONT VILLA MALTON
All that Valuable Leasehold MESSUAGE, or DWELLING-HOUSE, known as Claremont Villa, The Mount, Malton, and lately occupied by Miss Masterman. The House contains on the ground floor Dining, Drawing, and Breakfast Rooms, and Library. On the basement, a good Kitchen, Scullery, and all necessary Out-offices. On the first and second floors are eight good Bedrooms and w.c.; also two small Rooms suitable for Bathrooms. The house is supplied with gas and water, is in first-class repair, and ready for immediate occupation. There is a carriage laid drive in the front. The grounds are well laid out, planted with fine shrubs and good fruit trees, and the whole premises are surrounded with a substantial stone wall. the premises are leasehold of Earl Fitzwilliam for the unexpired term of 92 years, at a ground rent of £2002 per annum
York Herald, 15 October 1874
TO BE SOLD BY AUCTION
BY MESSRS. T. BOTTERILL & SON
At the TALBOT HOTEL, MALTON, on TUESDAY, the 12th of OCTOBER, 1880, at TWO for THREE o’Clock in the Afternoon precisely (subject to such Conditions as shall be then produced and read).
ALL that capital MESSUAGE or DWELLING HOUSE called “ROCKINGHAM HOUSE” situated on the Mount, in the parish of Old Malton, in the Borough of Malton, in the County of York, with large Garden and all necessary Outoffices belonging thereto, late in the occupation of Mr. William Thompson, now deceased.
The house is handsomely and substantially built of stone, contains large Dining, Drawing, and Breakfast Rooms, Eight Bed Rooms, Bath Room, W.C., Kitchen, Scullery and Cellar, and is in every way adapted for a gentleman’s residence.
There is a good supply of water laid on. The house Is in one of the best situations in Malton, and within five minutes’ walk from the Railway Station.
Malton is within easy distance of and immediately connected by rail with York, Scarbro’, Whitby, Thirsk, and Driffield; and is about five miles from Castle Howard. It is one of the best Hunting Centres in Yorkshire, being in the midst of Lord Middleton’s Hunt, and the York and Ainsty, Sir Harcourt Johnstone’s, and, the Sinnington Hounds meet within a few miles. The Property is Leasehold for a term of 90 years, commencing on the 6th April, 1870.
The House may be viewed on application to the AUCTIONEERS, Castlegate, Malton; and further Particulars obtained of them, and at the Offices of MR. J.D. WHITEHEAD, Solicitor, Pickering. Pickering, 23rd September, 1880.
Yorkshire Gazette, 22 October 1880
This was advertised for sale by auction in the Malton Messenger, 25 February 1922. While clearly a substantial property it is not clear that it had gas or electricity services.
DETACHED VILLA RESIDENCE
Known as No. 8, The Mount, Malton, late in the occupation of Mr. Thomas Stabler, with the gardens and conservatory, and yard adjoining, embracing an area of 2,244 square yards or thereabouts. The dwellinghouse comprises dining and drawing rooms, kitchen, scullery, 2 larders, spacious entrance, stairs and landing, three bedrooms, bathroom and w.c. room, and box room.
In the yard there is a detached washhouse, coalhouse, and w.c. In the front adjoining the house there are two vineries, with entrance from the hall. The property is pleasantly situate, and the front rooms face west and south. The property is leasehold for 99 years from the 6th April, 1864, and subject to the small annual ground rent of 4. Immediate possession can be arranged to be given. The lease is open to inspection during office hours, at the office of the vendor's solicitor. For permission to view and further particulars apply to the Auctioneers, Malton; or to SAMUEL RIDGE, Solicitor, Malton
Yorkshire Post and Leeds Intelligencer, 5th October 1901
No 20 Contents for Sale
Mr William Hopper Nicholson, former Malton stationmaster, following his retirement lived at 20 The Mount. His executors disposed of his furniture etc in June 1900
The 1861 Census shows Thomas Parke as a 'corn merchant' at Great Habton. However, the Yorkshire Gazette  records Thomas's death at The Mount, Malton, on 8th May 1865. It looks likely that Thomas and his family were the first occupants of no 27 The Mount. The 1871, 1881, 1891, 1901 and 1911 Censuses show Thomas's son, Robert Rotherford Parke and his family living there. In June 1911 Robert's mill at Amotherby burned down 
At some point the house was converted into flats but in 2019 the house was restored/refurbished and was offered for sale in 2020.
-  Yorkshire Gazette, 13 May 1865
-  Baker's Chronology 1899-1911
Rockingham House was advertised for sale or let in the York Herald, 2 May 1881, containing drawing, dining, breakfast, 8 bedrooms, bathroom, kitchen, scullery, cellar, and large garden.
In 1939 Rockingham House was rented by the Urban District Council for purposes of the evacuation scheme  In 1946 it was advertised for sale by auction with W.C. and Coal Shed, Gas and towns water. Electric power is adjacent but not laid on 
-  Yorkshire Post and Leeds Intelligencer, 26 October 1939
-  Yorkshire Post and Leeds Intelligencer, 24 August 1946