1.  Blaine R. Bake, ed.  1996.  Marriage Index: AZ, CA, ID, NV, 1850-1951.  (Broderbund CD-225):  not found.

2.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #5 of 9):  Town of Quincy, Plumas Twp., Plumas Co., CA, Roll T9-0070, p. 404A, PN 5, SD 3, ED 81, enumerated 2 Jun 1880, official enumeration date 1 Jun 1880 (extracted by Diana Gale Matthiesen):

1880:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).
1	2	3	4	5	6	8	9	10	13	24	25	26
27	26	Light Marcus S	W	M	31			/	Blacksmith	PA	PA	PA
		_____ Annie L	W	F	26	Wife		/	Keeping house	VT	VT	VT
		Boring Katie R	W	F	6	S dau	/		At home	CA	KY	VT

3.  1890 Census:  the 1890 census population schedules were destroyed.

4.  1900 Census Every-Name-Index/Images (online at Ancestry.com, Image #13 of 18):  Plumas Twp., Plumas Co., CA, Roll 96, p. 50A, SN 7, SD 3, ED 102, enumerated 27-29 Jun 1900, official enumeration date 1 Jun 1900 (extracted by Diana Gale Matthiesen):

1900:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).

1

2

3

4

5

6

7

8

9

11

12

13

14

15

19

20

21

22

23

24

25

26

27

174

178

Garland Silvia

Head

W

F

Mar 1849

51

Wd

2

2

NJ

SWE

GER

Y

Y

Y

O

F

H

Light Marcus S

Boarder

W

M

Jul 1848

51

Wd

PA

PA

PA

Blacksmith

0

Y

Y

Y

_____ William B

Boarder

W

M

Jun 1881

18

S

CA

PA

VT

Blacksmith

0

Y

Y

Y

_____ Dela E

Boarder

W

F

Mar 1888

12

S

CA

PA

VT

At School

6

Y

Y

Y

5.  1910 Census Every-Name-Index/Images (online at Ancestry.com, Image #19 of 26):  Plumas Twp., Plumas Co., CA, Roll T624_91, p. 67, SN 19A, SD 1, ED 79, enumerated 11 May 1910, official enumeration date 15 Apr 1910 (extracted by Diana Gale Matthiesen):

1910:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).
1	2	3	4	5	6	7	8	9	10	11	12	13	14	17	18	19	20	21	22	23	24	26	28
176	187	Light Sylvia	Head	F	W	61	Wd2	41	5	2	New Jersey	Germany	Germany	Eng	Boarders	Home	OA	N	0	Y	Y	O	H
		_____ William B	Son	M	W	29	S				California	Pennsylvania	New Jersey	Eng	Blacksmith	Shop	W	N	0	Y	Y

Sylvia's father was born in Sweden.  William is Sylvia's stepson, not her son, and his mother was born in Vermont.

6.  1920 Census Index/Images (online at Ancestry.com):  can't find Sylvia.  William Byers LIGHT is married and living in Mineral, Plumas Co., CA.

7.  California State Board of Health, Bureau of Vital Statistics. Certificate of Death.  Filed 17 Dec 1906.  County of Plumas, Quincy, California.

Name: Marcus Stein Light Date of Birth: July 16, 1848; Birthplace: Pennsylvania Date of Death: Dec 13, 1906; Place of Death: Quincy, Plumas Co. Cause of Death: cardiac paralysis Place of Burial: Quincy Cemetery Undertaker: Kinsy & Smith, Quincy Occupation: Blacksmith & machinist Name of Father: Adam Light Maiden Name of Mother: Susan Stein Informant: Mrs. L.O. Yarner, Quincy, Calif.

8.  California State Board of Health, Bureau of Vital Statistics. Certificate of Death.  Filed 20 Aug 1923.  County of Plumas, Quincy, California.

Name: William Byers Light Date of Birth: June 2, 1881 Birthplace: California Name of Father: Marcus Light; Birthplace: Penn Maiden Name of Mother: Anna Parker; Birthplace: Vermont

9.  Civil War Soldiers and Sailors System.  National Park Service (online at www.itd.nps.gov/cwss/ and at Ancestry.com as U.S. Civil War Soldiers, 1861-1865):

Name:	Marcus S. Light
Side:	Union
Regiment State/Origin:	Pennsylvania
Regiment Name:	103 Pennsylvania Inf.
Regiment Name Expanded:	103rd Regiment, Pennsylvania Infantry
Company:
Rank In:	Private
Rank In Expanded:	Private
Rank Out:	Private
Rank Out Expanded:	Private
Film Number:	M554 roll 71

10.  Civil War Pension Index (index and images online at Ancestry.com):

Name of Soldier	Light, Marcus S.
Name of Dependent	Widow	Light, Silvia
	Minor
Service	G 103 Pa Inf
Date of Filing	Claim	Application No.	Certificate No.	State from which Filed
	Invalid
1907 June 8	Widow	871095		Calif
	Minor

Pension applications often contain significant genealogical information, so it would probably be worth obtaining a copy.

11.  Public Member Trees (online at Ancestry.com).