As a dividend investor, I’m always on the lookout for stocks with high and safe yields that can boost my portfolio’s returns. After a recent search of several industries, I came across three great stocks with yields of 3-6%, so I added them to my watch list. Let’s take a quick look at each to determine if they belong on your watch list as well or if you should take it one step further by establishing a position in one of them today.

1. Parkland Fuel Corp.

Parkland Fuel Corp. (TSX:PKI) is one of North America’s leading distributors and marketers of fuels and lubricants, including gasoline, diesel, propane, and heating oil. It pays a monthly dividend of $0.0945 per share, or $1.134 per share annually, which gives its stock a yield of about 5.3% at today’s levels.

It is also important to make two notes.

First, Parkland has raised its annual dividend payment for three consecutive years, and its recent increases, including its 5% hike in March, has it on pace for 2016 to mark the fourth consecutive year with an increase.

Second, I think the company’s ample distributable cash flow, including an adjusted $1.47 per share in fiscal 2015, could allow it to announce another dividend hike in the second half of this year.

2. Sun Life Financial Inc.

Sun Life Financial Inc. (TSX:SLF)(NYSE:SLF) is the third-largest insurance company in Canada with over $891 billion in assets under management. It pays a quarterly dividend of $0.39 per share, or $1.56 per share annually, which gives its stock a yield of about 3.7% at today’s levels.

It is also important to make two notes.

First, Sun Life raised its annual dividend payment by 4.9% in 2015 to $1.51 per share, its first annual increase since 2008, and it is currently on pace for 2016 to mark the second consecutive year with an increase.

Second, the company has a medium-term target dividend-payout range of 40-50% of its underlying net income, so I think its very strong growth, including its 27% year-over-year increase to $3.76 per share in fiscal 2015, could allow it to announce another dividend hike within the next few months.

3. Transcontinental Inc.

Transcontinental Inc. (TSX:TCL.A) is Canada’s largest printer, and it is one of the country’s leading providers of proximity media solutions. It pays a quarterly dividend of $0.185 per share, or $0.74 per share annually, which gives its stock a yield of about 3.6% at today’s levels.

It is also important to make two notes.

First, Transcontinental has raised its annual dividend payment for 14 consecutive years, and its recent increases, including its 8.8% hike in March, has it on pace for fiscal 2016 to mark the 15th consecutive year with an increase.

Second, I think the company’s strong growth in cash flows from continuing operations, including its 37.8% year-over-year increase to $34.3 million in its first quarter of fiscal 2016, could allow it to announce another dividend hike later this year.

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Fool contributor Joseph Solitro has no position in any stocks mentioned.