Additional information that might be helpful, from some available R. L. Polk's Portland City Directories, and a marriage record I found. The library I visited didn't have all the years of the city directories available. Some or none of the following may help you.
1890, page 486
STRYKER, David S., dentist & physician, 1971 1st, res 224 3rd.
STRYKER, George, stereotyper, rms 330 2nd.
STRYKER, Guy, appr, Oregonian, rms 330 2nd.
STRYKER, Mrs. Maria, res 111 F.
STRYKER, Ola, res 330 2nd.
STRYKER, Ray S., electrotyper, bds 330 2nd.
STRYKER, Wm H., machhan, J. C. Carson, bds 283 N 11th.
1897, page 594
STRYKER, David S., dentist 141 1/2 1st, res 450 E Clay.
STRYKER, Edward, lab, r 661 Oregon.
STRYKER, George W., dentist D. S. Stryker, rms 141 1/2 1st.
STRYKER, Guy Q., comp, res Milw.
STRYKER, Mrs. Maria A., res 315 Flanders.
STRYKER, Wm H., sash & door mkr, bds 889 Hendricks av.
[Research Note: The residence for Guy is listd as Milw. This would be a small town south of Portland called Milwaukie. This shows Guy lived in Milwaukie and worked in Portland.]
1904, page 889
STRYKER, Annie M. (wid David S.) bds 442 E 11th.
STRYKER, Marie A. (wid Wm) bds 265 6th.
STRYKER, Stanton W., dentist 141 1/2 1st, res 585 Leo Av.
I wish there had been more directories available with years surrounding these years, because that sure would have helped. Is it possible William and Maria lived in a town other than Portland, or that they were divorced? By 1903 the Marie A. STRYKER says she is a widow. But, this lady might not be your relative. The 1897 shows a William who was a "sash and door" maker.
I found the following reference to Maria in the Multnomah County Marriage Book #4, June 1879-June 1883, page 149, in the Rare Book Room at the library of the Genealogical Forum of Oregon:
Date of Marriage: 19 March 1881
Marriage at the home of Joseph BARB.
Marriage of: Patrick CALL [name wasn't clear so could be CULL] of Wasco County, State of Oregon, and Mary RAEHL of Multnomah County, Oregon.
In the Presence of Mrs. Joseph BARBARE and Maria STRYKER, by R. E. BYBEE, JP.
[Research Note: Regarding the information that the marriage was at the home of Joseph BARB. His surname was spelled BARB on the record. Regarding the witness, Mrs. Joseph BARBARE, her surname was spelled BARBARE on the record. Could any of these people be related to your William and Maria STRYKER?]
If David S. STRYKER was related to your William H. and Maria A. STRYKER, here is the information I found, on the microfilm, of some old death certificates for deaths in the City of Portland. Microfilm was found at the library of the Genealogical Forum of Oregon (GFO), in Portland Oregon: Roll #8, #22764:
Name: David S. STRYKER
Born: NY, NY.
Died: 20 May 1899 in Snohomish, Washington.
Residence: 272 Multnomah St., Portland.
Lived in Portland 15 years
Previous Residence: Drain, Oregon
Buried: Lone Fir Cemetery
Undertaker: Finley & Son
[Research Note:Drain, Oregon is in Douglas County, and is about 6-8 miles west of the I-5 Freeway at the junction of Highway 99 and Highway 38.Snohomish is in Snohomish County, Washington. It is north and east of Seattle, and about 10 miles southeast of Everett, off of Highway 2. I didn't find any record of a William H. STRYKER in this microfilm of early deaths in Portland. The State of Oregon started recording deaths in 1903.]
Could the surname also be spelled STRIKER?