Ancestry.com did not index Monongahela TWP, Greene County, Pennsylvania for the 1870 census.  I was
able to manually find the following Hartly families there in 1870:

1870 Census - Greene County, Pennsylvania
Monongahela TWP - 8 June 1870

  96 96
  Hartly, Josephus   61 M W Farmer 8150 2730 Pa
  Sarah              58 F W Keeping House    Pa
  Rebecca E.         19 F W At Home          Pa
  Oscar              16 M W At Home          Pa
  Thompson, Rebecca  36 F W Domestic Servant Pa

  97 97
  Hartly, Samuel     63 M W Farmer 14000 1925 Pa
  Elizabeth          57 F W Keeping House     Pa
  Harriet            22 F W At Home           Pa
  Stephen            24 M W Labors on Farm    Pa
  Mary               26 F W At Home           Pa
  Josephine          20 F W At Home           Pa
  Rebecca            18 F W At Home           Pa
  Amanda             16 F W At Home           Pa
  Worthington, Vincent 31 M W Labors on Farm   Pa
  ---, Hanna         30 F W At Home           Pa
  Hyde, Hiram        40 M W                   Pa
  Wells, William     11 M W Labors on Farm    Pa
  Thompson, Minor     8 M W                   Pa

1840 Census - Greene County, Pennsylvania
Monongahela TWP

  Nancy Hartly
  1 Female under 5
  1 Female 5-10
  1 Female 15-20
  1 Female 30-40

  Mary Hartly
  1 Female 10-15
  1 Female 70-80

1850 Census - Fayette Co., PA Nicholson TWP

  59 59
  Joseph Y. Provence 21 M Farmer 1500 PA
  Rachel             65 F             Del.
  Amelia             17 F             PA

  61 61
  Theoren Provence   28 M Farmer 1500 PA
  Maria              25 F             PA
  Elvira              7 F             PA
  Joseph N.           5 M             PA
  James C.            3 M             PA
  Nancy            9/12 F             PA
  Lydia Hartley      12 F             PA

  73 73
  John Ache          38 M Farmer 7000 PA
  Martha             31 F             PA
  Jefferson          11 M             PA
  Louisa              9 F             PA
  Hannah              6 F             PA
  Mary J. Hartley    21 F             PA
  James              20 M Laborer     PA
  Jefferson Ferren   17 M Do          PA
	
1856 - IGI - Children of Theron Spencer Provance and Ann Mariah Hartley

  Theron Spencer Provance
  bn. 8 May 1856 Masontown, Fayette, PA
  source: #1260895 Batch 8114707 sheet 32

1860 Census - Fayette Co.,PA Nicholson TWP

  208 208
  Theren Provance  40 M Farmer 2000 350 PA
  Ann              36 F                 PA
  Elvira           17 F                 PA
  Joseph           15 M                 PA
  James            13 M                 PA
  Nancy            11 F                 PA
  Benjamin          9 M                 PA
  Lewis             7 M                 PA
  Theren            5 M                 PA
  Rachel            3 F                 PA

  209 209
  Reuben Parschall 34 M  Farmer      PA
  Mary Hartly      30 F  Housekeeper PA

  220 220
  Martha Ache      45 F Farmer   7000 500 Pa
  Jefferson        21 M do                Pa
  Louisa           18 F                   Pa
  Hannah           17 F                   Pa
  Mary             75 F                   Va

  224 224
  Nancy Hartley   59 F            PA
  James Hartley   26 M    Cropper PA
  Eliza           25 F            PA

  Springhill TWP
  1748 1746
  Benj Province   48 M D. Lab. - 400 PA
  Sarah           43 F               VA
  Saline          20 F               PA
  Jas. L.         18 M Cripple       PA
  David           18 M D. Lab.       PA
  Joana           12 F               PA
  Benj.           10 M               PA
  Jesse            8 M               PA
  Nancy J.         8 F               PA
  Sarah E.         5 F               PA
  Jno. C. Herman Province 5/12 M     PA

1870 Census - Fayette Co., PA Nicholson TWP

  182 191
  Provins, H.M.   46 F Keeping House  PA
  J.H.            23 M                PA
  J.M.            22 M                PA
  N.C.            20 F                PA
  Ben F.          18 M                PA
  Lewis           16 M                PA
  Theren          14 M                PA
  Rachel          11 F                PA
  Hartly, Nancy   64 F                PA

1880 Census - Fayette County, Nicholson TWP, PA District 47

  34 34
  Provance, Mariah  W F 55 Widowed Keeping House PA PA PA
            Rachael W F 21 Dau Single            PA PA PA

  42 42
  Provance, Joseph H.   W M 34 Laborer PA PA PA
            Anne E.     W F 29         PA PA PA
            Lenora      W F  8         PA PA PA

1880 Census - Allegheny County, Pennsylvania
McKeesport - District 40

  191 206 Drumond Square Hotel
  Province, Louis   W M 26  Boarder Blacksmith          Penn Penn Penn

1900 Census, Fayette County, Nicholson TWP PA Prec #2

  34 34
  Provance, Joseph H.  Head W M Aug 1846 53 M 29    PA PA PA
     Ann E.            Wife W F Oct 1850 49 M 29    PA PA PA
  Pinder, Nora         Dau  W F Mar 1872 28 M 6 2 2 PA PA PA
          Lester       Son  W M Nov 1886 13 S       PA PA PA
          Paul R       GSon W M Oct 1894  5 S       PA England PA
          Hellen W     GDau W F Oct 1897  2 S       PA England PA

1920 Census - Wyandotte County, Kansas
Kansas City Ward 6 - 3 January 1920

  1041 77 84 Harbrook Ave.
  Hoover, Joseph L.
  ...
  Provance, Lewis F.  Boarder M W 66 M WVa  Penn WVa  Laborer at Soap Plant

misc. - Fair View Cemetary Headstone, Masontown, Fayette, Pa
	
  Provance, Theron S.	1854-1930  {these two together}
  Provance, Cora B.		1865-1956
  Katherine Provance Vosburgh	1895-1975
  Charles H. Provance	1900-1953
  Provance, Davis A.	1870-1957  {these two together}
  Provance, Mollie		1870-1952
	
  Malinda, wife of Joseph Y. Provins died Aug 25, 1883 in the 70, year of her age

misc.  - Cyclopedia of Fayette Biographies by Ellis (?)

  p. 521  James M. Provance was born in Nicholson township, Fayette county, 
  Pa., March 23, 1849;  was reared on a farm, and attended the common 
  schools.  At the age of thirteen, he commenced to make his own living as 
  deck sweeper on a steamboat, which he followed for one year, when he 
  shipped as deck hand, after which he worked as a fireman for some time.  
  He was engaged upon the river for about ten years, when he engaged in 
  mining coal.  Afterwards learned the trade of stone mason.

  In 1872 he was married to Mis Mary M. Romesburg, a daughter of Adam 
  Romesburg, who was a native of Pennsylvania, and of German descent.  Mrs. 
  Provance died Sept. 4, 1887.  To this union were born five children: 
  Alfrida, Isa D., Della, Harry B. and James L.  Alfrida is married to 
  Daniel Davis of Fayette County.

  Mr. Provance owns a comfortable little home at New Geneva.

  Theron Provance, the father of the subject of this sketch, was born in 
  Fayette county Pa., owned a small farm, and had a comfortable home.  His 
  father, Joseph Y. Provance, was one of the early settlers of western 
  Pennsylvania, and was a large land owner.  He was of English birth, and 
  came to America, and settled in Pennsylvania before the revolution, and 
  took part in that war.  He was the father of twenty-seven children.